How do military chaplains perceive the legitimacy of US drone strikes? Since the terrorist attacks of 9/11, after which the US adopted drones to kill terrorists, scholars have explored public perceptions of legitimate drone warfare (Lushenko and Raman Reference Lushenko and Raman2024; Barela Reference Barela2015). In doing so, they have adopted a legal-rational or moral definition of legitimacy. In legal-rational terms, perceptions of legitimate drone strikes are shaped by their compliance with international law (Vald and Hardy Reference Vlad and Hardy2024; Blank Reference Blank2023; Clark Reference Clark2007; Dill Reference Dill2015). On the other hand, the jus in bello (justice in war) principles of distinction, necessity, and proportionality shape perceptions of morally legitimate drone strikes (Lushenko Reference Lushenko2022). Despite or because of scholars’ focus on public opinion toward US drone strikes, they have not seriously investigated how members of the US military perceive the legitimacy of these operations.
Most scholars tap into the attitudes of Americans to proxy for public perceptions of legitimate drone strikes, arguing that the US’ prolific use of drones makes its citizens a barometer for global public opinion (Kreps Reference Kreps2014). Few studies explore the attitudes of other countries’ citizens for these operations (Alparone et al. Reference Alparone, Kantorowicz and Klein2025; Ceccoli and Bing Reference Ceccoli and Bing2018), including those targeted by US drone strikes (Silverman Reference Silverman2019). While a handful of studies also investigate soldiers’ attitudes toward drones (Lin-Greenberg Reference Lin-Greenberg2022; Macdonald and Schneider Reference Macdonald and Scheider2019), no study has explored the attitudes of practitioners responsible for justifying the use of drones, particularly chaplains assigned to the US Army. The US Army is the backbone of the US military, synchronizing operations globally, and the US Army is responsible for executing a majority of US drone strikes (Magula Reference Magula2022; Lushenko et al. Reference Lushenko, Van Auken and Stebbins2019).
This oversight is puzzling. By regulation, chaplains are entrusted to shape the moral use of force during conflict (Joint Chiefs of Staff 2022; Chief of Staff of the Army 2015). Chaplains are trained in Just War Tradition and International Humanitarian Law to serve as advisers to commanders weighing the merits of US drone strikes (Alley Reference Alley2024; Leonard Reference Leonard2020; Patterson Reference Patterson2014). This expertise means that chaplains constitute “moral advocates” during combat (Loveland Reference Loveland and Bergen2004). Hassner (Reference Hassner2010, 203) argues that religion, enshrined in chaplains as the religious stewards of the US Army, can influence “the legitimacy of weapons and targets.”Footnote 1
To study chaplains’ perceptions of legitimate US drone strikes, we use a novel survey experiment among a rare sample of chaplains drawn from across the US Army, including its Active Duty, National Guard, and Reserve components. We assess chaplains’ attitudes toward US drone strikes when varying two key attributes for these operations. These include the certainty standard for civilian casualties, ranging from lower (near-certainty) to higher (reasonable-certainty) expectations of collateral damage, and the location of strikes across internationally recognized (declared) and non-internationally recognized (undeclared) theaters of operations, such as Iraq and Yemen. These two mechanisms frame patterns of drone strikes that chaplains inform and advise through their counsel to commanders.
Our analysis of the data reveals several findings. First, while chaplains’ understandings of the legitimacy of US drone strikes in terms of their perceived legality and morality largely covary, variation in the whereabouts of strikes can cause chaplains to emphasize their legality. We find that chaplains discount the legal-rational legitimacy of strikes in undeclared theaters of operations, even when they are tightly constrained through the near-certainty standard to minimize civilian casualties. In terms of US drone strikes, this finding provides the first experimental evidence for an intuition shared among philosophers that sometimes “the morally right thing to do is illegal and…the legally permissible option is immoral” (Chapa Reference Chapa and John2018, 186). Second, regardless of chaplains’ perceived legality or probity for US drone strikes, they can support them less, viewing them as counterproductive. This is especially pronounced for what chaplains perceive to be the most legitimate pattern of drone warfare, which we call stringent battlefield strikes—operations conducted in declared theaters of operations with rigorous oversight. Finally, we find some variation among chaplains for legitimacy outcomes. We show that a handful of instrumental, normative, and operational considerations exercise an effect on chaplains’ beliefs. These include beliefs about the use of force globally, the perceived moral obligation to use strikes globally, and the potential for political officials’ abuse of drones. We also observe that chaplains’ combat experiences reduce their perceptions of legally versus morally legitimate strikes.
The remainder of this article unfolds in four parts. First, we introduce a middle-range theory that differentiates between patterns of US drone strikes based on their constraint and location, which helps inform theoretical expectations about chaplains’ beliefs for these operations. Next, we discuss our research design that connects chaplains to the situational and geographic contexts of US drone strikes, which experts on religion and international security refer to as neo-Weberianism (Lynch Reference Lynch2009). Our research design consists of a survey experiment among a unique sample of US Army chaplains. Integral to this design is our understanding of legitimacy as a sociological rather than normative outcome, meaning it is empirically testable and not a function of experts’ claims for what they perceive is an appropriate use of force in terms of drones (Price Reference Price2023). We then present our results before concluding with the policy, research, and military readiness implications of our findings.
Theoretical Framework
Defining Drone Warfare
Scholars conceptualize drone warfare in four ways. Some scholars conflate drone warfare with drone platforms themselves, such as the MQ-9 Reaper. This results in “drone essentialism” (Gusterson Reference Gusterson2019) where drones are “a fetishized object of state desire” (Biswas Reference Biswas2014, 110). Other scholars relate drone warfare to counter-terrorism, reflecting the purpose of US military operations since 9/11 (Jackson Reference Jackson2023). Still, other scholars characterize drone warfare as “targeted killing,” which refers to the use of surgical strikes to remove high-value targets, such as terrorist leaders (Jadoon et al. Reference Jadoon, Mines and Milton2022; Meisels and Waldron Reference Meisels and Waldron2020). Finally, a handful of scholars equate drone warfare to remote warfare, though this concept is broader and incorporates a range of standoff capabilities, including cyber (Renic Reference Renic2020).
Yet US political and military leaders use drones to “aid, watch, and kill” (Welsh Reference Welsh, Cortright, Fairhurst and Wall2015), meaning that the strategic context of conflict shapes how and where drones are used (Horowitz et al. Reference Horowitz, Kreps and Fuhrmann2016). As such, scholars increasingly differentiate between varying uses of drones. They note that drones can be used tactically or strategically (Chapa Reference Chapa2022). Pollack and Byman argue that drones have “become the US tactic of choice in more and more situations, to the point where they are sometimes elevated to the default strategy itself” (Reference Pollack and Byman2024, 41). Scholars also argue that drones can be used for self-defense or in support of multinational operations (Brunstetter Reference Brunstetter2021); integrated with other capabilities, such as missiles and rockets (Rogers Reference Rogers2024a); and, in retributive or anticipatory ways. These latter approaches are designed to impose punishment for grievances or prevent a forecasted threat (Braun Reference Braun2023). Though countries can constrain drone strikes differently, and use them in different theaters of operations, scholars have not studied the implications of these attributes for legitimacy outcomes, and certainty not in the context of US Army chaplains’ counsel to commanders.
First, drone strikes can be constrained with multilateral or unilateral oversight. Multilateral constraints obligate countries to meet the oversight requirements of allies and partners, which are imposed through a deliberate authorization for the use of drones during conflict. United Nations’ (UN) approval for drones, which characterized French strikes in Mali (King Reference King2023), is thought to impose stricter targeting protocols enforced during an inclusive coordination process involving political and military officials from many countries. According to Huan (Reference Haun, Haun, Jackson and Schultz2021, 12), “[c]oalitions may deal with collateral damage concerns by granting nations veto power over strikes or by allowing nations to opt out of particular missions.” Unilateral constraints, imposed by political officials within a single country and exercised by military commanders in terms of rules-of-engagement (ROE), relate to different certainty standards for the possibility—if not likelihood—of collateral damage, namely civilian casualties (Crawford Reference Crawford2013). These constraints, preferred by US officials, consist of varying reasonable-certainty and near-certainty standards governing the likelihood of civilian casualties. Republican presidents have adopted the more permissive reasonable-certainty standard; Democratic ones have conditioned strike approval on the near-certainty of no civilian casualties (Regan Reference Regan2022).
Second, countries also use drones in different theaters of operations. These include declared and undeclared theaters of operations. The former, often referred to as active or internationalized conflict zones such as Afghanistan from 2001–2021, are sanctioned by the UN and have intervening countries’ forces deployed on the ground. The latter, often referred to as non-active or non-internationalized conflict zones such as Pakistan, are not sanctioned by the UN nor do they typically have intervening countries’ forces deployed on the ground. Given these distinctions, Gusterson (Reference Gusterson2015) conceives of “pure” and “mixed” drone warfare, noting drones can be used separately from or in support of deployed forces. Bridging these ideal types to concerns for systemic racism globally (Búzás Reference Búzás2021), Brunstetter (Reference Brunstetter2025) argues that a veritable “drone contract” informs countries’ use of drones in other countries’ territories, which can vary between “colorblind” and “racialized” consent. Pure drone warfare best characterizes the US’ over-the-horizon strikes that some scholars also claim are based on racialized consent (Cachelin Reference Cachelin2022).
Patterns of US Drone Strikes
Integrating the constraint and location mechanisms reflects four patterns of US drone strikes (Figure 1). Strikes conducted in undeclared theaters of operations and with reasonable-certainty constitute a form of lenient over-the-horizon strikes. This pattern best characterizes US drone strikes in Pakistan under the Bush administration, imposing higher levels of harm on civilians. According to the Bureau of Investigative Journalism (BIJ) (2024), the Bush administration conducted 51 strikes from 2004 to 2009 in Pakistan, resulting in 269–461 civilians killed and another 175–277 injured. This amounted to between 9 and 11 civilians killed or injured per strike, contradicting the chief benefit of drones—enhanced precision. Indeed, some war ethicists claim that precision is a euphemism for radical asymmetry that constitutes morally problematic killing (Renic Reference Renic2020).Footnote 2 Lenient over-the-horizon strikes are often based on nothing more than “intelligence signatures—patterns of behavior that are detected through signals intercepts, human sources and aerial surveillance, and that indicate the presence of an important operative or plot against US interests” (Miller Reference Miller2012).
Strikes conducted in undeclared theaters of operations with near-certainty reflect a model of stringent over-the-horizon strikes, which characterizes US drone strikes in Pakistan under the Obama administration from 2011 to 2018. Following his inauguration in 2008, Obama adopted the Bush-era model of permissive strikes in Pakistan, which resulted in 263 strikes from 2009 to 2011 that killed or injured nearly 1,250 civilians (BIJ 2024). Obama conducted three times as many strikes in his first two years in office as Bush conducted throughout his entire second term, resulting in five civilian casualties per strike. By 2011, the surge in civilian casualties encouraged Obama to adopt the near-certainty standard (Friedersdorf Reference Friedersdorf2016). Contrary to criticism that Obama’s “stricter limitations on drone strikes seem to have had an effect only at the margins” (Jaffer Reference Jaffer2016), the policy shift was effective, and further enabled by improved technology and learning across the US military (White Reference White and Primoratz2007; Plaw et al. Reference Plaw, Fricker and Williams2011). The adoption of these “personality” strikes, meaning operations were predicated on intelligence that confirmed the identity of the target, reduced the rate of civilian casualties, enhanced the precision of strikes, and saved hundreds of Pakistanis (Raman et al. Reference Raman, Lushenko and Kreps2021).
Strikes conducted in declared theaters of operations with reasonable-certainty reflect lenient battlefield strikes while strikes conducted in declared theaters of operations with near-certainty reflect stringent battlefield strikes. Since 9/11, presidents have adopted these patterns, often using them simultaneously in active conflict zones, including Afghanistan and Iraq (Jadoon et al. Reference Jadoon, Ton and Rice2024; Boyle Reference Boyle2020). In addition to operational considerations, including the availability of drones and munitions, the perceived value of targets shapes commanders’ use of these models. High-value targets, characterized by their importance to an enemy’s network and missions, often encourage lenient versus stringent battlefield strikes based on the anticipated military gains, including the disruption or defeat of enemy networks (Hardy and Lushenko Reference Hardy and Lushenko2012).
Figure 1. Patterns of US drone strikes.
Theoretical Expectations
What are the implications of these patterns of US drone strikes for US Army chaplains’ understanding of legitimacy? For some experts, chaplains’ attitudes toward US drone strikes may not matter (Jost et al. Reference Jost, Kertzer, Min and Schub2024; Klocek and Hassner Reference Klocek, Hassner and Patterson2014). Research shows that “chaplains have found past attempts to advise military commanders on tactical and operational objectives to be ‘difficult at best’” (Klocek and Hassner Reference Klocek, Hassner and Patterson2014, 212). Hassner (Reference Hassner2016, 88) notes that “there is no evidence of chaplains constraining, or even claiming to have constrained war,” which other research also suggests (Lee Reference Lee2024). More alarmingly, Hassner (Reference Hassner2016, 98) finds that “[f]ew chaplains have felt that it was their responsibility to place moral constraints on combat.” The military’s martial culture also risks discounting chaplains’ advice, which can contradict commanders’ targeting prerogatives making chaplains “vulnerable to censure” (Loveland Reference Loveland and Bergen2004, 237). Similarly, research shows that chaplains can be hawkish, using their reverent authority to justify illegal if not immoral operations through acts of commission (endorsement) or omission (silence). Hassner (Reference Hassner2016) refers to these behaviors as force multipliers.
Even so, studying chaplains’ beliefs is important for several reasons (Gopin Reference Gopin2002). High levels of religiosity in the US military suggest that commanders may draw on chaplains’ counsel, either directly or indirectly, when authorizing drone strikes (Besse Reference Besse2019). Hassner (Reference Hassner2016, 7) notes that “religion has indirectly influenced U.S. planning and performance by shaping the interests of U.S. troops, their opponents, and third parties.” In October 2016, a US Army chaplain, Captain Chris Antal, resigned in protest over the US drone program. His resignation, in which he submitted a letter to then-President Barack Obama, signaled frustration with US drone strikes and sent shockwaves across the US Army (Skinner Reference Skinner2017). Chaplains also minister to soldiers who operate drones, and research suggests that these operators are vulnerable to “moral injury” due to their use of drones (Philipps Reference Philipps2022). According to VanderZanden (Reference VanderZanden2024, 59), “drawing on symbolic rituals such as fire, water…and the rule of prayer, chaplains offer the awareness of painful experiences and participate in symbolic cleansing” when ministering to drone operators. Finally, studying chaplains’ attitudes toward drones sheds new light on questions about how they understand emerging technologies, the implications of these capabilities for future conflict, and the consequences for global security, which constitute new areas of research for religion and war studies (Patterson Reference Patterson2014). As such, we follow Hassner’s (Reference Hassner2016) lead by adopting chaplains’ beliefs as our unit of analysis in navigating perceptions of legitimate US drone strikes.
Existing research suggests that public perceptions of legitimate drone strikes are strongly shaped by civilian casualties. Regan (Reference Regan2022, 317) argues that minimizing civilian casualties is a “precondition for the perceived legitimacy of…strikes.” Dill (Reference Dill2015) contends that distinction, where commanders differentiate between combatants and noncombatants while conducting drone strikes, informs legitimate targets that have implications for perceptions of rightful wartime conduct. Ron et al. (Reference Ron, Lavine and Golden2019) also show that public support for drones can be offset when strikes kill civilians, and Eichenberg (Reference Eichenberg2019) finds that this effect is more pronounced among female versus male observers of these operations. Lushenko and Raman (Reference Lushenko and Raman2024) capitalize on these insights to employ a survey experiment in France and the US, allowing them to determine cross-national variation in public perceptions of legitimate drone strikes. French citizens prefer a judicious model of internationally approved strikes regardless of the potential for civilian casualties. Americans perceive strikes conducted unilaterally, without external oversight, as most legitimate, especially because these operations are designed to enhance national security (Chu and Williamson Reference Chu and Williamson2025). When these strikes result in civilian casualties, however, Americans’ perceptions of legitimacy are shaped by external oversight.
The same is true of fully autonomous drones, or “killer robots” that can identify, track, and target objects on their own (Horowitz and Maxey Reference Horowitz and Maxey2025; Halpern Reference Halpern2022). Research shows that US citizens’ attitudes toward support are mostly moderated by error-proneness, with target misidentification resulting in civilian casualties reducing public support the most (Rosendorf et al. Reference Rosendorf, Smetana and Vranka2023, Reference Rosendorf, Smetana, Vranka and Dahlmann2024). This is consistent with other research that finds the precision of drones augmented with Artificial Intelligence (AI) enhances public support for their use the most (Kreps et al. Reference Kreps, George, Lushenko and Rao2023), including perceptions of legitimacy (Waldman and Martin Reference Waldman and Martin2022). These outcomes are likely to be similar, if not more pronounced, among chaplains. Chaplains are drawn from the American public. At the same time, their training and expertise make them attuned to the potential consequences of US drone strikes, especially for operations that are purposefully used in anticipation of civilian casualties. While investigating the role of religion on the modern battlefield, one team of researchers found that “chaplains have the training, skills, credentials, and accessibility” to commanders to reinforce the principle of distinction during military operations, including for drone strikes (Lee et al. Reference Lee, Burke and Crayne2005, 14). These insights suggest our first empirically testable hypothesis, which we also preregistered:
H1: The near-certainty standard enhances chaplains’ perceptions of morally legitimate strikes.
Myriad studies also suggest that compliance with international law exercises a strong shaping effect on public support for US drone strikes. Kreps (Reference Kreps2014) found that the perceived compliance with international law shapes US citizens’ support for strikes, which subsequent studies echo. Schneider and Macdonald (Reference Schneider and Macdonald2016) found that Americans support strikes when they are perceived to comply with domestic and international law. Kreps and Wallace (Reference Kreps and Wallace2016) further found that international and non-governmental organizations, especially the UN, can shape public support for drone strikes, particularly when their criticisms concern the legality, rather than effectiveness, of these operations.
Scholars have extended these findings to inform studies of the public’s perceptions of legitimate drone strikes. First, Lushenko et al. (Reference Lushenko, Raman and Kreps2022) found that international approval for drone strikes shapes understanding of their legitimacy among American and French citizens. Second, related studies show that perceived compliance with international law also shapes public perceptions of legitimacy for semi-autonomous (Lushenko and Kreps Reference Lushenko and Kreps2022) and fully autonomous drones (Lushenko Reference Lushenko2024b). Third, Lushenko and Raman (Reference Lushenko and Raman2024) found that international law exercises a strong shaping effect on American and French perceptions of legitimate strikes. This is ironic in terms of Americans, considering their preferred pattern of over-the-horizon strikes flouts the chief norm of international relations—countries’ sovereignty or territorial integrity. Finally, in the context of AI-enhanced capabilities, Lushenko (Reference Lushenko2024a) also finds that soldiers’ trust in partnering with them is shaped by their perceived compliance with international law.
Compliance with international law is likely to exercise a strong shaping effect on chaplains’ perceptions of legitimate US drone strikes as well. In his resignation letter, Antal criticized the US drone program for “extraconstitutional authority and impunity for international law,” justifying his refusal to “serve as an Empire chaplain” (Goodman Reference Goodman2016). Antal’s focus on international law reflects broader beliefs within the chaplaincy corps, which chaplains channel through their ministry to soldiers and counsel to commanders. According to Pope Francis, formerly head of the Catholic Church, chaplains “have a duty to ensure that the norms established by international humanitarian law be accepted by the men and women in uniform they are entrusted to serve” (Esteves Reference Esteves2019). Archbishop Edwin F. O’Brien emphasized this special responsibility while serving as the co-adjutor of the Archdiocese of the US Military Services from 1997 to 2007. He argued, “[w]here there is an acceptance of direct killing of noncombatant civilians, for instance, there is no chaplaincy worth its name” (Catholic Review 2012).
Therefore, chaplains’ most preferred model of US drone strikes, measured by the highest outcomes for perceptions of legal and moral legitimacy, will likely be that which attempts to minimize civilian casualties the most while maximizing adherence to international law in terms of the declared theater of operations. Hassner (Reference Hassner2016), though critical of chaplains’ advisory role during war, finds that chaplains exercise an important moral brake on the use of force against opponents’ sacred sites, such as burial grounds and worshipping places. Operations at these sacrosanct locations, especially, cause chaplains to “agonize over the moral dilemmas” that they confront as advisers to commanders (Hassner Reference Hassner2016, 100). These dilemmas also reflect chaplains’ awareness of the military’s legal requirement to minimize civilian casualties, the likelihood of which increases when US drone strikes are used in unsanctioned conflict zones. This discussion informs two additional empirically testable hypotheses, with the latter moving beyond our preregistration:
H2: Non-active conflict zones reduce chaplains’ legal-rational perceptions of legitimate strikes.
H3: Chaplains will perceive stringent battlefield strikes as the most legitimate pattern of strikes.
Research Design
To test these expectations, we administered a survey experiment in February 2024 among a representative sample of US Army chaplains.Footnote 3 This resulted in 283 high-quality responses, affording strong statistical power for our experiment, which is not typically the case for surveys that use elite samples (Blankenship Reference Blankenship2025; Blankenship and Lin-Greenberg Reference Blankenship and Lin-Greenberg2022; Casler Reference Casler2024). Our survey followed a 2x2 factorial and between-subject design with four experimental vignettes presented to the respondents. These experimental groups exposed chaplains to fictional but realistic US drone strikes that varied based on their certainty standard and location, with research suggesting that hypothetical but realistic scenarios do not negatively affect the validity of the results (Brutger et al. Reference Brutger, Kertzer, Renshon, Tingley and Chagai2023).
Respondents were told, “Since the terrorist attacks of 9/11, the US military has adopted a [near-certainty/reasonable-certainty] targeting standard while using drones to strike terrorists in [declared/undeclared] theaters of operations.” Next, respondents were told, “This means that commanders’ approval of drone strikes is based on the likelihood of [no/some] civilian casualties and the operations take place in conflict zones that are [sanctioned/neither sanctioned] by the United Nations [and/nor] have US boots on the ground.” To ensure that we met the requirement of a randomized-controlled trial, which is helpful to reduce bias (Angrist and Pischke Reference Angrist and Pischke2015), we included a control group that did not manipulate these strike attributes. Respondents assigned to the control group were only informed, “Since the terrorist attacks of 9/11, the US military has used drones to strike terrorists abroad.”
Following the randomized vignette, we probed three dependent variables. These include chaplains’ perceptions of rightful conduct and legality of US drone strikes under these circumstances, corresponding to moral and legal-rational understandings of legitimacy, as well as how supportive chaplains are of these operations. We asked chaplains to gauge their attitudes toward how rightful and legal they believe US drone strikes are under these circumstances, as well as their support, using an ordinal, five-point Likert scale ranging from one (low) to five (high). We randomized the order of these questions to protect against chaplains conflating these attitudes. Though it is possible that chaplains equate moral and legal-rational perceptions of legitimacy, as well as attitudes of support, our results suggest that they do not, reflecting strong effects for our intention-to-treat (Mutz Reference Mutz2011). We then include a series of questions that help us assess if other considerations, including values and beliefs that scholars refer to as “microfoundations” (Kertzer Reference Kertzer2017), also shape chaplains’ attitudes. These questions relate to instrumental, normative, and operational factors that we draw from the voluminous literature on drone warfare (Rogers Reference Rogers2024b), including chaplains’ considerations for the use of force, the ethics of drones, and the manner of chaplains’ service. It is possible that this approach could impose post-treatment bias. In other words, chaplains’ responses to attitudinal questions could be influenced by our earlier treatments. To minimize the potential for post-treatment bias, we shortened the length of our survey, adopting an approach suggested by recent political methodology research (Sheagley and Clifford Reference Sheagley and Clifford2023).
Still, we hesitate to draw sweeping generalizations from our findings. First, though the US Army is the largest branch of the US military, and conducts the most drone strikes abroad, it is possible that our results do not account for chaplains’ attitudes across the US military. Second, surveys are liable to priming and social desirability bias, wherein respondents are encouraged to answer in a certain way or do so because of the perceived pressure to do so (Stantcheva Reference Stantcheva2023; Mutz Reference Mutz2002). Given the sensitivity of our vignettes, as well as our unique sample of chaplains, this could be a concern because respondents may discount or embellish their beliefs considering their special advisory role. Finally, do chaplains’ responses explain their attitudes in the real world, which informs the external validity of our results? This issue of treatment effect can be exacerbated by “satisficing,” in which chaplains take the survey quickly, thus reflecting a broader concern for attentiveness (Alvarez et al. Reference Alvarez, Atkeson, Levin and Li2019).
To address these potential limitations, and consistent with Kane’s (Reference Kane2024) and Stantcheva’s (Reference Stantcheva2023) counsel, we incorporate hypothetical but realistic scenarios and include stronger treatments to reduce the potential for priming among chaplains. We also run several robustness checks by adding an attention check; accounting for fast (less than one minute) and slow (over ten minutes) survey completion times (Bowen et al. Reference Bowen, Goldfien and Graham2022; Read et al. Reference Read, Wolters and Berinsky2022); and, calculating average marginal effects, measuring the average predicted change in chaplains’ perceptions of legitimacy across the experimental groups (Bailey Reference Bailey2017). We also interpret our results as “latent treatment effects,” responding to criticisms of poor construct validity and measurement error in survey experiments, meaning our main outcome variable of interest—legitimacy—is an indicator of a latent variable that cannot be directly observed (Stoetzer et al. Reference Stoetzer, Zhou and Steenbergen2024). In the online appendix, we show that our results are largely robust considering these checks.
We analyze the data in four ways. Consistent with Kreps et al. (Reference Kreps, George, Lushenko and Rao2023), we first assess how the certainty standard, conditioned on the location of operations, shapes chaplains’ perceptions of legitimate drone strikes when comparing the experimental groups to the control group. This analysis only provides a descriptive result—percent change. Thus, we then run two-tailed t-tests, allowing us to calculate if chaplains’ mean responses to each experiment group, when compared with each other and the control group, are statistically distinguishable. Calculating these difference-in-means is a parametric test, such that chaplains’ responses are assumed to be normally distributed. We fulfill this assumption by drawing from the Central Limit Theorem. This theorem explains that with enough data, generally understood as more than 30 observations per treatment group, which we have, the sampling distribution tends to be normally distributed (Angrist and Pischke Reference Angrist and Pischke2015). We cross-reference these main results using the non-parametric Wilcoxon test, which assumes our data violates the normality assumption. We observe that the results from these parametric and non-parametric tests are consistent, further validating our overall findings.
Next, we interrogate chaplains’ responses using Ordinary Least Squares (OLS) regressions, adopting an approach used by Krebs et al. (Reference Krebs, Ralston, Balzacq, Blagden and Shenhav2025), Lushenko and Raman (Reference Lushenko and Raman2024), Musgrave and Ward (Reference Musgrave and Ward2023), and others. We regress chaplains’ treatment group assignments against legitimacy outcomes while also incorporating demographic variables and other factors that may affect chaplains’ attitudes toward US drone strikes. Further, we replicate an approach used by Kreps and Wallace (Reference Kreps and Wallace2016) by estimating an ordered probit regression model. We use the five-point measures of legal and moral legitimacy as dependent variables, where higher values indicate greater levels of perceived legitimacy. We model these outcomes across all treatment groups, using the control group as a referent, and include the same demographic variables and covariates used in our OLS regressions. In the online appendix, we show that our main results are robust when interrogating the data through an ordered probit regression model, and Wald tests reinforce the statistical significance of our findings. Finally, we use text-as-data (Grimmer and Stewart Reference Grimmer and Stewart2013), drawing from chaplains’ feedback on an open-ended question where we ask them to explain the factors they considered when evaluating the legitimacy of US drone strikes.
Results
Main Results
Our results provide strong support for two of our hypotheses, including H2 and H3. Though only partially supportive, the findings for H1 also shed new light on chaplains’ attitudes toward drones. In terms of H1, we find that the near-certainty standard does enhance chaplains’ perceptions of morally legitimate drone strikes. We also find that chaplains’ understanding of rightful wartime conduct in the context of drone warfare can be moderated by the theater of operations, with undeclared conflict zones reducing chaplains’ perceived probity of strikes the most. According to the descriptive results presented in Figure 2, chaplains’ perceptions of morally legitimate strikes increased relative to the control group, but only for stringent battlefield strikes (7.3%). Figure 2 also shows that chaplains’ perceptions of morally legitimate strikes decreased for all other patterns of drone warfare, including for lenient battlefield strikes (−5.9%), lenient over-the-horizon strikes (−18.2%), and stringent over-the-horizon strikes (−7.8%). Thus, when drones are used in declared theaters of operations and under the near-certainty standard, chaplains view them as more morally legitimate than other patterns of US drone strikes, offering partial support to H1 in terms of these descriptive results.
Figure 2. Percent change in chaplains’ perceptions of morally legitimate US drone strikes relative to the control group.
We further explore the statistical significance of these descriptive findings for H1. Figure 3 displays the mean level of chaplains’ perceptions of morally legitimate strikes for different patterns of US drone warfare relative to the control group, which is reflected by a dashed line. We compare outcomes for chaplains’ average perceptions of morally legitimate strikes between each experimental group and the control group using two-tailed t-tests. We find that the outcomes are statistically significant for increases in chaplains’ perceptions of morally legitimate drone warfare in terms of stringent battlefield strikes (p = .03) and decreases in chaplains’ perceptions of morally legitimate drone warfare in terms of lenient over-the-horizon strikes (p = .003). We also find that chaplains’ perceptions of moral legitimacy are not statistically significant for the remaining two patterns of US drone warfare—lenient battlefield strikes (p = .13) and stringent over-the-horizon strikes (p = .22).
Figure 3. Chaplains’ mean perceptions of morally legitimate US drone strikes relative to the control group. Vertical I-bars represent 95% confidence intervals. * p < 0.10, ** p < 0.05, *** p < 0.01.
These results are consistent when conducting pairwise t-tests, in which we compare chaplains’ perceptions of moral legitimacy across experimental groups, finding statistically significant differences between stringent battlefield strikes and both—battlefield and over-the-horizon—forms of lenient strikes (p < .001), as well as stringent battlefield and over-the-horizon strikes (p < .001). As we also show in the online appendix, these results are mainly driven by Christian chaplains, with the data showing that Catholic priests are more permissive of US drone strikes in terms of their perceptions of moral legitimacy, especially for lenient battlefield strikes. This finding corroborates Hassner's analysis (Reference Hassner2016). He finds that Catholic priests can be more aggressive on the battlefield. Together, these results suggest that undeclared theaters of operations exercise both a substantively and statistically significant moderating effect on chaplains’ perceptions of morally legitimate drone warfare, though this effect is more pronounced for strikes that are conducted under the reasonable-certainty rather than the near-certainty standard. Indeed, one chaplain noted that “reasonable certainty is not quite strong enough to condone the loss of human life beyond a very minimal amount.”
The data also offers strong statistical support for our expectations for H2 and H3. In terms of H2, we find that non-active conflict zones further reduce chaplains’ legal-rational perceptions of legitimate drone warfare. According to Figure 4, the use of drones in undeclared theaters of operations sharply reduces chaplains’ legal-rational perceptions of legitimacy for both stringent and lenient over-the-horizon strikes, and by approximately the same double-digit margin (−20.0%). Drones used in declared theaters of operations under the reasonable-certainty standard, that is, lenient battlefield strikes, slightly reduce chaplains’ perceptions of legal-rational legitimacy (−1.8%). On the other hand, drones used in declared theaters of operations under the near-certainty standard, meaning stringent battlefield strikes, increase chaplains’ perceptions of legal-rational legitimacy (7.2%). As reflected in Figure 5, these purely descriptive results are also largely statistically significant, and at the p < .02 level or below. However, we also find that chaplains do not differentiate between the control group and lenient battlefield strikes in terms of legal-rational perceptions of legitimacy (p = .66). Similar to our results above, we further find that pairwise t-tests reinforce these findings, with the statistical difference between stringent battlefield strikes and both—lenient and stringent—forms of over-the-horizon strikes being more pronounced (p < .001) than for other combinations of experimental groups.
Figure 4. Percent change in chaplains’ perceptions of legally legitimate US drone strikes relative to the control group.
Figure 5. Chaplains’ mean perceptions of legally legitimate US drone strikes relative to the control group. Vertical I-bass represents 95% confidence intervals. * p < 0.10, ** p < 0.05, *** p < 0.01.
Combined, these results demonstrate that chaplains perceive stringent battlefield strikes as most legally and morally legitimate, as we anticipated in H3. Drones used in declared theaters of operations under the near-certainty standard resulted in the most favorable legitimacy outcomes among chaplains, in both legal-rational and moral terms. Not only were these outcomes descriptively stronger than for other patterns of strikes, but they were statistically stronger as well. Moreover, chaplains’ feedback on the open-ended question relating to their thoughts on legitimacy outcomes for US drone strikes reflects that “US boots on the ground,” coupled with the “declared combat zone,” strongly shapes their overall perceptions. Here, too, we find that Christian chaplains are more conservative in their views than chaplains of other denominations. Christian chaplains are especially critical of the perceived legality of strikes conducted in undeclared conflict zones, even when they are tightly constrained (see online appendix).
These outcomes are consistent when analyzing our data in an OLS regression framework. Table 1 shows the association between patterns of US drone strikes and chaplains’ perceptions of morally legitimate operations as coefficients from an OLS regression, which we replicate for chaplains’ legal-rational perceptions of legitimacy in Table 2. These coefficients represent the magnitude of chaplains’ perceptions of morally and legally legitimate strikes considering a one-unit increase in a given variable when controlling for all other considerations. Overall, the results offer strong statistical support to H2 and H3, confirming our expectations for the implications of undeclared theaters of operations for chaplains’ legal-rational perceptions of legitimate strikes as well as their preference for stringent battlefield strikes in terms of both—legal and moral—considerations of legitimacy.
Table 1. OLS Regression Results: Moral Legitimacy
+ p < 0.10, * p < 0.05, ** p < 0.01, *** p < 0.001. OTH = over-the-horizon.
Table 2. OLS Regression Results: Legal Legitimacy
+ p < 0.10, * p < 0.05, ** p < 0.01, *** p < 0.001. OTH = over-the-horizon.
As reflected in Model 1 of Table 2, we find a consistent substantive and statistically significant reduction in chaplains’ legal-rational perceptions of legitimate strikes when drones are used in undeclared theaters of operations, and with both the near-certainty (β = −0.76, p < .001) and reasonable-certainty (β = −0.67, p < .001) standards. Chaplains perceive strikes as less legally legitimate when they are used in non-conflict zones regardless of the targeting standard. These results are replicated in additional models, which add controls for demographics (2); party affiliation and partisanship (3); instrumental and normative factors that research (Horowitz and Maxey Reference Horowitz and Maxey2025; Lin-Greenberg Reference Lin-Greenberg2022; Fisk et al. Reference Fisk, Merolla and Ramos2019; Kreps and Wallace Reference Kreps and Wallace2016) shows can shape public attitudes toward drones (4); and, military experiences (5). We also find a consistent substantive and statistically significant increase in chaplains’ perceptions of legally and morally legitimate drone warfare in terms of stringent battlefield strikes. All models of Table 2 reflect that chaplains perceive US drone warfare as most legally legitimate when the practice is used in terms of stringent battlefield strikes. This result is most pronounced in Model 5 of Table 2 (β = 0.38, p < .05), which adds all relevant instrumental, normative, and operational factors, and is mirrored in Table 1. Across all models of Table 1, chaplains perceive stringent battlefield strikes as most morally legitimate, and at virtually the same magnitude in Model 5 (β = 0.37, p < .05).
We also draw on our OLS regressions to identify other factors that can shape chaplains’ attitudes toward US drone strikes. Across Tables 1 and 2, we find little effect for demographic considerations on chaplains’ perceptions of legally and morally legitimate strikes in the setting we study, except sex. When controlling for all other factors, female chaplains are more likely to discount the legal and moral legitimacy of strikes, and this effect is more pronounced in terms of chaplains’ legal-rational versus moral perceptions of legitimacy. Whereas this effect loses statistical significance moving beyond Model 3 of Table 1 (β = −0.62, p < .05), it remains acute across all models of Table 2, including our most robust Model 5 (β = −0.65, p < .05). To be fair, female chaplains only account for 2% of our sample, meaning the attitudes of these religious stewards exercise an outsized effect on overall legitimacy outcomes when aggregating across all respondents. Even so, this finding reinforces existing research showing that biological sex can shape motivations for violence, with women consistently favoring the use of force in global politics less than their male counterparts due to their fundamental “ethics of care” (Gilligan Reference Gilligan1982; McDermott Reference McDermott2015). It also echoes findings by Eichenberg’s (Reference Eichenberg2019) that females consistently discount their support for drone strikes compared to men, and favor these operations less than other forms of force, such as peacekeeping.
Legitimacy versus Support
We extend our study to assess potential differences between legitimacy and support outcomes, wherein chaplains may perceive patterns of US drone warfare as legally and morally legitimate but not support them as much. We find that chaplains perceive stringent battlefield strikes as most legitimate in terms of the alignment between, and magnitude of, legal and moral legitimacy outcomes. Compared to other experimental groups, and according to Pearson’s correlation test, the correlation between chaplains’ perceptions of legal and moral legitimacy is the highest—0.77 (p < .001). This is consistent with the results of a t-test, wherein we find no statistically significant difference between chaplains’ mean perceptions of legal and moral legitimacy in terms of this pattern of US drone strikes (p = .89). Yet chaplains’ attitudes of support differ from their perceptions of legitimacy in ways that are not comparable to other experimental groups. Though chaplains may perceive stringent battlefield strikes as legitimate, they support them less, though the level of support is higher than for other patterns of strikes.
We show this outcome in several ways. First, as reflected in Figure 6, the correlations between chaplains’ perceptions of legal and moral legitimacy, and attitudes of support, are the lowest for stringent battlefield strikes. They consist of 0.51 (p < .001) and 0.50 (p < .001), respectively. Second, as reflected in Figure 6 as well, and compared to their attitudes of support, we find statistically significant differences in chaplains’ perceptions of legal-rational (p < .01) and moral (p < .02) legitimacy for stringent battlefield strikes. Finally, as reflected in the online appendix, we use logit regression models to find that chaplains are approximately 25% likely to reflect differences in their perceptions of legitimacy compared to their attitudes of support for stringent battlefield strikes. In other words, respondents perceive this model of drone warfare as legally and morally legitimate but do not support it as much, and this outcome is greater than the predicted probabilities of differences between chaplains’ perceptions of legitimacy and attitudes of support for all other patterns of US drone strikes.Footnote 4
Figure 6. Chaplains’ mean perceptions toward US drone strikes across all attitudes—legal legitimacy, moral legitimacy, and support. Vertical I-bars represent 95% confidence intervals.
To the extent these outcomes are consistent with other experimental groups, we observe deviations between chaplains’ perceptions of legal-rational legitimacy and support for stringent over-the-horizon strikes, as well as chaplains’ perceptions of legal-rational legitimacy and support for lenient battlefield strikes, with these outcomes running in opposite—negative and positive—directions. These findings are helpful to reinforce the implications of the type of—undeclared—theater of operations for chaplains’ perceptions of legally legitimate strikes, especially. But in only one case, stringent battlefield strikes, are the legitimacy outcomes uniformly different than chaplains’ attitudes of support, reflecting higher degrees of legal and moral perceptions of legitimacy compared to outcomes of support. These results beg the question—why?
Microfoundations
To explore the mechanisms that may underlie these findings, we use a combination of statistical and qualitative analysis. Our regression analysis reveals that chaplains’ perceptions of legally and morally legitimate strikes are shaped by several instrumental, normative, and operational considerations. As reflected in Model 5 of Tables 1 and 2, the most important instrumental consideration is the support to the use of force abroad, which can enhance chaplains’ perceptions of legally (β = .21, p < .01) and morally (β = 0.20, p < .01) legitimate strikes. The more chaplains support the use of force abroad, the more likely they are to endorse the legitimacy of strikes in legal and moral terms. Consistent with other respondents, one chaplain argued that the “USA is the only capable power to defend freedom around the world.” Chaplains are also more likely to perceive strikes as legally (β = 0.16, p < .01) and morally (β = 0.25, p < .001) legitimate when they believe that the US has a moral obligation to intervene abroad, which conditions chaplains’ moral versus legal perspectives more. Similar to other respondents, one chaplain noted “God has given government the power of the sword to stop evil doers. Drone strikes which kill known terrorists are a ‘good kill’ and is pleasing to God.”
Yet these beliefs are counterbalanced by several other considerations, reflecting chaplains’ differentiation between legal and moral perceptions of legitimate US drone warfare. Chaplains’ beliefs that drones will be abused by leaders dampen their perceptions of legitimacy, exercising strong effects in terms of both legal (β = −0.22, p < .001) and moral (β = −0.22, p < .001) legitimacy outcomes. One chaplain noted drones are “prone to abuse or overuse.” Another added drones allow officials to “act as the judge, jury, and executioner.” Still another chaplain argued drones “have made us sloppy which will absolutely cost us in the next few generations.” Chaplains’ considerations of international law, as well as their combat experiences, most expose the Janus-faced nature of their perceptions of legitimacy, which respondents explicitly recognize. One chaplain argued “just because a matter is legal, does not always mean that it is moral,” which echoed another chaplain who claimed “I understand they [drones] are legal, but I have ethical issues.”
Chaplains who believe that it is important for drone strikes to uphold international law perceive them as less morally legitimate (β = −0.17, p < .05), which is inconsistent with their perceptions of legal legitimacy, reflecting the way chaplains inscribe morality within the laws of armed conflict as well as targeting practices in the US Army. One chaplain reasoned that “in accordance with a moral law of war, and the use of violence not happening in declared or sanctioned warzone, the moral legitimacy seems to suffer.” Another chaplain argued that legitimacy “is eroded because commanders are not equipped/trained on the difference between something being legal, moral, and/or ethical…they stop at the JAG [military lawyer] when they hear something is legal. They shelve the other two (usually moral and ethical).”
We also find that combat experience exercises the strongest effect on chaplains’ perceptions of legal versus moral legitimacy, with this crucible event greatly reducing beliefs of legally legitimate strikes (β = −0.32, p < .10). Consistent with research on military attitudes toward AI (Lushenko Reference Lushenko2024a, Reference Lushenko2024b), this finding suggests that physical proximity to conflict can also shape perceptions of legitimacy due to the vividness of experiences (Yarhi-Milo Reference Yarhi-Milo2014). Reflecting on combat shaped the most visceral feedback from chaplains. One respondent noted, “war is hell—striking military targets in conflict is always legitimate, no matter what the method.” Another chaplain acknowledged that legitimate strikes reflect “violence of action in order to protect American lives.” Yet these operations did not shape chaplains’ perceptions of moral legitimacy in terms of combat experience, suggesting concerns with the radical asymmetry drones are thought to impose on targets.
We further analyze qualitative data gathered through an open-ended question to gain more leverage over the microfoundations of chaplains’ attitudes, thus replicating an approach adopted in recent studies on public opinion for drones (Lin-Greenberg Reference Lin-Greenberg2022). We asked chaplains to explain the factors they considered when evaluating their legitimacy for US drone strikes and hand-coded the responses into one of ten categories drawn from the literature on drones (Rogers Reference Rogers2024b), removing any incomprehensible feedback.Footnote 5 Our ten categories included (1) drones’ unique capabilities; (2) a consideration of civilian casualties; (3) the perceived obligation to protect friendly forces; (4) the veracity of intelligence; (5) the perceived legality of strikes; (6) emphasis on criminal prosecution; (7) martial virtues, such as battlefield courage; (8) the perceived threat to the US; (9) presidential authority to execute strikes grounded by Article II of the US constitution; and, (10) countries’ sovereignty. Consistent with our main results, our analysis of chaplains’ open-ended responses shows several instrumental, normative, and operational considerations that are remarkably stable across the experimental groups (Table 3). The results help clarify differences in chaplains’ perceptions of legitimacy and attitudes of support, which we find is most pronounced for stringent battlefield strikes. We use caution when interpreting chaplains’ feedback. Chaplains’ answers may reflect social desirability bias given their status as moral stewards of the military. One respondent contended chaplains are “charged with morals and ethics of our armed forces,” suggesting chaplains are likely to respond in ways that they think outside observers would want or expect. Anecdotal evidence also suggests that chaplains are often at the extreme margins of their respective denominations in terms of permissive or conservative beliefs on the use of force abroad, which our results reflect as well.Footnote 6
Table 3. Chaplains’ feedback by experimental group
With this caveat in mind, we find that chaplains calibrate their perceived legitimacy of US drone strikes against the intended benefits of drones to remove targets while preventing civilian casualties. Similar to others, one chaplain opined that “minimization of civilian causalities” shaped legitimacy outcomes. Chaplains also emphasized the legality of strikes as the basis of their perceptions of legitimacy, further reflecting the way in which they can embed moral considerations within the laws of armed conflict. Like other chaplains, one argued that legitimate strikes “must comply” with international law. Finally, chaplains stressed the importance of intelligence to ensure “PID,” or the positive identification of targets, further reflecting a preference for the near-certainty standard. When strikes are conducted in undeclared theaters of operation, meaning they are over-the-horizon, we observe two additional themes. Chaplains cite the perceived threat to the US and countries’ territorial integrity as the basis of their perceptions of legitimacy. These findings echo research by Brunstetter and Férey (Reference Brunstetter, Férey, Lushenko, Bose and Maley2022). They discuss an “arc of strategic sovereign possibilities” to differentiate the implications of drones for sovereignty, arguing that drones can both stiffen and erode countries’ territorial integrity.
To more systematically analyze chaplains’ feedback, we also use word associations.Footnote 7 This is useful to identify what words frequently appear together within a body of text, therefore revealing which words are strongly associated with others based on how often they co-occur. To conduct this analysis, we first remove English “stopwords” from chaplains’ feedback. These are words that are commonly used but provide little information, such as “like.” Next, we remove special characters and confusing punctuation from chaplains’ feedback, as well as interrogative pronouns and superfluous adjectives and adverbs that provide little meaning. Having rendered a usable term-document matrix, we then use the “findAssocs” package in R to identify the words most correlated with chaplains’ feedback in terms of their perceived legitimacy for US drone strikes. Finally, we plot these results (Figure 7).
Figure 7. Word associations for chaplains’ perceived legitimacy of US drone strikes.
We observe that high-frequency words used by chaplains to explain their perceived legitimacy for US drone strikes largely corroborate our hand-coding of their responses. Chaplains frequently reference how “lawful” US drone strikes are, thus reflecting consideration of international law when interrogating the perceived legitimacy of these operations. Chaplains also frequently mention the “intelligence” justifying US drone strikes, as well as the “ethical” and “moral” use of drones, especially in terms of the type of—declared versus undeclared—“warzone.” Similarly, they acknowledge the potential for US drone strikes to impose unintended consequences among civilians, especially “suffering,” which reflects the importance of noncombatant immunity in shaping perceptions of legitimate operations. Together, these results help clarify key instrumental, normative, and operational considerations that shape chaplains’ perceptions of legitimate US drone strikes.
Discussion
These results offer the first experimental evidence for how US Army chaplains perceive the legitimacy of US drone strikes, in terms of both legal and moral considerations and relative to their attitudes of support. While scholars have studied the legitimacy of US drone strikes, they often conflate the legal and moral dimensions of legitimacy, privileging one aspect over the other in drawing conclusions for overall legitimacy outcomes (Vlad and Hardy Reference Vlad and Hardy2024); do not investigate the relationship between these two dimensions, how it may shift due to the context of conflict, and the implications for attitudes of support as well; and, draw on primarily US citizens to assess public attitudes toward drones. Thus, scholars have largely ignored military samples, including chaplains. Yet these military practitioners may view strikes differently than citizens based on how and where they are used, and these beliefs may have implications for shaping drone policy and strategy as well (Zwald et al. Reference Zwald, Kennedy and Ozer2025).
However, we acknowledge that our results may be limited in several ways. Our sample of US Army chaplains, precisely because it is rare, may limit the external validity of our results across the US military and cross-nationally, among allied and partnered militaries. Though we think it is unlikely given the strength of our results, it is possible that the status of chaplains’ service could distort our findings in ways we did not anticipate. Given the US Army’s recruitment protocol, we did not stratify chaplains according to their service—Active Duty, National Guard, and Reserve—component. As we note above, military chaplains can also be more dogmatic than their civilian counterparts suggesting they may hold less conservative views on the use of force in terms of drones than we may otherwise presume. Similarly, our vignettes did not expose chaplains to patterns of drone warfare by name, from which chaplains gauged their perceptions of legitimacy and attitudes of support. Thus, it is possible that chaplains did not understand unique models of strikes as we intended, especially if they have never been directly exposed to drones. Typical of survey experiments that capture respondents’ attitudes toward drones, we also document chaplains’ beliefs at a discrete time, raising questions about the longevity of their views, especially as chaplains gain more experience. Finally, we did not ask chaplains’ where they thought the strike took place. This means we cannot rule out the possibility that chaplains’ prior beliefs about conflict zones shaped their attitudes, which could distort the construct validity of our results.
Our results, then, should be interpreted with caution. We offer a first stab at advancing the research agenda on religion and war studies, as well as on public opinion and drone warfare, both in terms of perceptions of legitimacy and among a unique group of military advisers. When integrated, our findings make several methodological, theoretical, and substantive contributions.
As opposed to sociological (Appleby Reference Appleby1999), securitization (Browning and Joenniemi Reference Browning and Joenniemi2017), or anthropological (Asad Reference Asad2007) approaches to the study of religion and violence, we adopt a neo-Weberian perspective. According to Lynch (Reference Lynch2014, 280), who draws from Weber’s constructivist insights and methodology introduced in Sociology of Religion (Reference Weber1963), this neo-Weberian approach conceives of religion as a practice and positions its manifestation within chaplains who “bridge the gap between doctrine, ethics, and action in particular contexts.” Such contextualization allows us to adopt innovative techniques to rigorously study chaplains’ perceptions of legitimacy for US drone strikes using empirically derived data, which builds on and advances existing studies (e.g., Lushenko and Raman Reference Lushenko and Raman2024). In doing so, we show that is possible to treat legitimacy as an outcome variable of interest in religion and war studies, similar to attitudes of approval and support, which scholars mostly study as dependent variables when using survey experimental research (Wu and Knuppe Reference Wu and Knuppe2016).
Similarly, we introduce novel data from a rare, and some might argue elite, sample of US Army officers relating to their attitudes towards drones, which research suggests is a consequential weapon of modern war (Calcara et al. Reference Calcara, Gilli, Gilli and Zaccagini2022). As such, we advance an emerging genre of experimental political science research among elites while bridging this approach to an untapped military sample of chaplains that are thought to exercise influence over military operations (Casler Reference Casler2024; Saunders Reference Saunders2024; Kertzer and Renshon Reference Kertzer and Renshon2022). At the same time, we have made this data publicly available to engender research that explores the evolution of drone warfare, and its normative implications, in new and novel ways that may further advance an emerging second-generation of research for public opinion and drone warfare. The first-generation, benchmarked by Kreps’ (Reference Kreps2014) path-breaking research, focuses on US citizens, emphasizes a bottom-up perspective on public opinion, and does not typically explore microfoundations. The second-generation advances beyond the first by broadening the respondent pool for surveys, to include military populations; exploring how elites can shape public opinion; and, investigating microfoundations (Lushenko Reference Lushenko and Rogers2024c).
Our study also makes several theoretical contributions. First, we problematize US drone warfare in terms of unique strike attributes, drawing on and integrating the constraint and location of operations to bound an original typology of patterns of US drone warfare, which researchers have not previously considered in an integrated fashion. Second, we draw on this multidimensional and explanatory framework (Collier et al. Reference Collier, LaPorte and Seawright2012) to inform testable expectations for the way that chaplains perceive the legal and moral legitimacy of drone warfare, thus decomposing legitimacy into two pathways that scholars often conflate. We take this investigation a step further by exploring how these legitimacy outcomes relate to chaplains’ attitudes of support given variation in how and where strikes are conducted. Our analysis reveals countervailing beliefs in terms of perceptions of legitimacy and attitudes of support, especially for stringent battlefield strikes, which further establishes perceptions of legitimacy as worthy of empirical research. Finally, we adopt multiple methods to conduct our analysis, including using text-as-data through an open-ended question posed to respondents. This allows us to triangulate data to ensure the greatest possible leverage over microfoundations that help explain chaplains’ overall attitudes.
Finally, we provide the first experimental evidence for how varying features of the constraint and location of US drone strikes shapes chaplains’ attitudes toward them. Scholars have studied the implications of religion on the battlefield (Hassner Reference Hassner2016) as well as global politics, including crisis escalation, conflict mediation, and war termination (Posada-Téllez Reference Posada-Téllez2024; Horowitz Reference Horowitz2009). The perceived legitimacy of US drone strikes held by chaplains responsible for shaping their use has been entirely understudied. Indeed, we know “surprisingly little” about what shapes legitimacy outcomes, especially among chaplains (Ceccoli and Bing Reference Ceccoli and Bing2018, 247). Even so, scholars argue that public perceptions of legitimacy are “potent” in shaping the durability of policy and strategy (Snyder and Diesing Reference Snyder and Diesing1977, 498; Price Reference Price2023); experts recognize that legitimacy is central to countries’ use of drones (Fang and Oestman Reference Fang and Oestman2022; Pan et al. Reference Pan, Yakhmi, Iyer, Strasnick, Zhang and Berstein2022; McDonald Reference McDonald2021; Lewis and Vavrichek Reference Lewis and Vavrichek2016); political and military officials characterize strikes as legitimate to sustain their use abroad, even when they inadvertently kill civilians (Aikins et al. Reference Aikins, Koettl, Hill, Schmitt, Tiefenthaler and Jordan2021); and, some analysts contend that lenient strikes, even in the event of civilian casualties, are legitimate (Vlad and Hardy Reference Vlad and Hardy2024). Even if we assume that chaplains matter little for drone strikes, high religiosity in the US military suggests that chaplains may exercise a structural effect across the ranks that can shape the use of force, meaning we should at least be aware of chaplains’ perceptions of legitimacy (Hassner Reference Hassner2016).
Ultimately, we find that chaplains’ perceptions of the legal and moral legitimacy of US drone strikes are generally concomitant. At the same time, we show that chaplains’ legal and moral perceptions of legitimate drone strikes can deviate, with variation in the whereabouts of strikes causing chaplains to discount especially their perceptions of legal versus moral legitimacy. Indeed, while undeclared theaters of operations can moderate chaplains’ perceptions of legitimate drone warfare, the results are only significant for a reduction of legal versus moral legitimacy outcomes for both patterns of stringent and lenient strikes.
Our discovery of differences between chaplains’ perceptions of legitimacy and attitudes of support, especially for stringent battlefield strikes, also advances existing research for the public’s paradoxical attitudes toward emerging technologies, both in war and across society. Lushenko and Raman (Reference Lushenko and Raman2024) found that while public attitudes of support and legitimacy can coincide in terms of different patterns of drone warfare, they can also deviate. This is similar to what other scholars call a “trust paradox” in terms of AI, in which people may support AI-enabled capabilities—such as driverless vehicles—but not trust them as much (Horowitz et al. Reference Horowitz, Kahn, Macdonald and Schneider2023; Kreps et al. Reference Kreps, George, Lushenko and Rao2023). The same is true of military attitudes for AI. Using a survey experiment, Lushenko (Reference Lushenko2024a) found that practitioners, particularly senior military officers with twenty or more years of service, are more supportive of the uptake of AI-enhanced technologies that they do not trust as much. Junior military personnel, namely cadets training to commission as officers, do not experience such a paradox of attitudes suggesting greater exposure to and fluency with technology (Lushenko and Sparrow Reference Lushenko and Sparrow2024). We draw on these studies by using several empirical methods to explain chaplains’ contrasting beliefs for drone strikes in the setting we study, and our findings show a remarkably consistent set of instrumental, normative, and operational considerations that underpin chaplains’ beliefs.
Conclusion
These results have important implications for policy, research, and military readiness. To better align chaplains’ overall attitudes with the current US policy of over-the-horizon drone strikes, which US citizens broadly endorse until mistakes are made, policymakers should more transparently discuss US drone policy. In doing so, they should explain the intelligence driving operations, risk mitigation measures, and how strikes comport with or deviate from international law. Policymakers should also explicitly justify a transgression of other countries’ sovereignty, should this happen in the course of using drone strikes, especially in terms of US national security.
Researchers should extend our study in several ways as well. First, how generalizable are our results across the US military and among allies and partners? Scholars should study the views of military lawyers toward drone strikes, considering they can also act as forces multipliers when advising commanders (Cohen Reference Cohen2025; Liddick Reference Liddick2021). Some defense experts argue that military lawyers play a more consequential role in commanders’ decision-making for targeting than do chaplains (Dunlap Jr. Reference Dunlap2024). There are also outstanding questions for how culture shapes perceptions of legitimacy and attitudes of support for drone strikes (Hofstede Reference Hofsted2001). Given the emergence of an era of coalition warfare (Kreps Reference Kreps2011), scholars should study the attitudes of chaplains—and soldiers more broadly—within allied and partnered militaries. In Pakistan, military religious advisers, known as Naib Khateeb, exercise tremendous influence over operations (Raja Reference Raja2024). European countries have also adopted more restrictive policies than the US on the use of drones (Dunn and Wheeler Reference Dunn and Wheeler2024). These examples suggest that our findings may have more salience in cross-national contexts.
Second, how do variations in other conditions shape attitudes toward drone strikes? How does the type of conflict, target, munition, objectives, outcomes, incorporation of AI, and approving authority, ranging from commanders to presidents, shape beliefs (Waldman and Martin Reference Waldman and Martin2022)? To what extent does the race of the target, in terms of its phenotypical and toponymic characteristics, namely skin color and location, moderate chaplains’ attitudes (Lushenko et al. Reference Lushenko, Carter and Bose2025)? Finally, if chaplains do not represent the moral advocates for the use of force that regulations empower them to be, as Hassner (Reference Hassner2016) contends, why not?
Our results also have important implications for military doctrine, training, and readiness. First, though they are regulatorily empowered to advise commanders on the use of force, it is unclear if chaplains’ opinions do matter. Thus, the US Army, as well as other services, should update regulations to reflect this reality or instruct commanders to meaningfully integrate chaplains into the targeting process. Second, we find that operational experiences prime chaplains to discount the legal versus moral legitimacy of drone strikes, suggesting that chaplains may be at risk of minimizing their special role to shape the moral use of force. On the other hand, we also find that chaplains can take pride in assuming a role as the moral stewards of the force. Future training should expose chaplains to this underlying tension. Future training should also integrate our findings to help expose differences in perceptions of legitimacy and attitudes of support that may be held by other members of military and intelligence staffs, who, like chaplains, can advise commanders deciding when, how, and where to use drones. Finally, our results can help inform chaplains’ counsel to soldiers, who may experience moral injury or post-traumatic stress disorder due to their work with drones, as well as their advice to commanders who may struggle with the legal, moral, and ethical implications of using drones, as many chaplains suggested they do. These challenges are likely to be exacerbated by the emergence of fully autonomous drones that are based on machine oversight of operations.
Supplementary material
To view supplementary material for this article, please visit https://doi.org/10.1017/S1755048325100084
Acknowledgments
The authors would like to thank Jennifer Alessio, William Alley, Alexandria Blackman, Tim Demy, James Dooghan, Charles J. Dunlap, Jr., Ron Hassner, Jamie Hickman, Mark Lee, Dayne Nix, Megan Price, Raja Wasim, Sean Wead, Xiang Zhou, and two anonymous reviewers for their comments and suggestions on an earlier draft of this article. The authors would also like to thank participants of workshops convened at the US Army War College in Carlisle, PA in June 2024 and the International Studies Association in Chicago, IL in March 2025 for their helpful feedback as well.
Competing interests
The authors declare none.
Paul Lushenko, PhD is an Assistant Professor at the US Army War College, Professorial Lecturer at The George Washington University, and Non-Resident Senior Fellow at Cornell University’s Brooks School Tech Policy Institute and Institute of Politics and Global Affairs. He is also an active-duty US Army officer and combat veteran, and the co-author of The Legitimacy of Drone Warfare: Evaluating Public Perceptions (2024).
Keith L. Carter, PhD is an Associate Dean at the US Naval War College and Non-Resident Senior Fellow at Cornell University’s Brooks School Tech Policy Institute. He is a retired US Army officer and combat veteran.
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