Introduction
The migration corridor between Mexico and the United States is the largest in the world. For decades, Mexico was fundamentally a country of origin for migrants; however, in the twenty-first century, it evolved into a country of transit, destination, and return. Migration through Mexico began to increase significantly from 2014 onwards, driven by the flow of people from Central America fleeing violence, poverty, and the effects of climate change.Footnote 1 Pressure on migration routes has intensified further with the arrival of extra-continental migrants, particularly those from African and Asian countries. People from Venezuela and the Caribbean, especially Haiti and Cuba, also use Mexican territory as a transit route to the United States.Footnote 2
The reconfiguration of Mexico’s migration profile has heightened its geopolitical relevance within the regional system of human mobility, particularly regarding its relationship with the United States. Mexico has become a key actor in the governance of transmigration flows, granting it potential leverage over its northern neighbour by virtue of its capacity to regulate these movements. This particular form of influence, exercised through the control of human mobility, is referred to in the literature as migration power.Footnote 3 This article analyses how such power was exercised in Mexico–United States relations during Donald Trump’s first administration (2017–21).
The study contributes to the migration diplomacy research agenda, which examines the strategic use of migration as a foreign policy tool. Within this field, particular attention has been paid to the role of structurally weaker states from the Global South that manage to influence stronger countries by using migration as a power resource to secure political or economic concessions. Influential contributions – drawing on neo-realist premises – explain states’ behaviour in terms of their position within the international migration system, whether as countries of origin, transit, or destination. They argue that states’ interests are shaped by this structural position and their relative power. From this perspective, transit countries are mostly expected to capitalise on their geographical location to obtain rewards in exchange for migration control agreements. This pattern is well supported by empirical evidence. Paradigmatic and widely studied cases include Turkey, Libya, and Morocco’s relations with the European Union.
The case of Mexico, however, draws attention to a less examined dynamic within this literature. Despite its influential geopolitical position and explicit incentives from the United States to pursue an aggressive migration containment policy, the Mexican government initially resisted instrumentalising its role as a transit country to extract benefits. That is, it rejected the possibility of using migration management as a strategic bargaining tool. Subsequently, Mexico yielded to external pressure but exercised its margin of influence in a defensive and deterrent manner, not to secure side payments but rather to minimise the costs that Trump threatened to impose on the bilateral relationship. Therefore, this case raises important analytical questions: what factors account for a transit country’s strategic decision to refrain from maximising its migration power, even when structural conditions and external incentives appear to favour it? What are the scopes and limits of transit countries’ migration power in the context of asymmetric relations with destination states?
This study advances the migration diplomacy literature by identifying the conditions under which transit states choose whether and how to activate or withhold their migration leverage. It develops a framework that examines strategic interactions between states through an understanding of power as influence between rational actors. The framework conceives decisions on whether and how to use migration power as cost–benefit assessments under specific structural constraints. It suggests that these evaluations depend on context and on how actors perceive their scope of action. This perspective helps to explain variations in the exercise of migration power across comparable settings.
The study’s contributions are twofold. Theoretically, it broadens the explanatory scope of migration diplomacy by moving beyond a focus on the rent-seeking behaviour of transit states to include strategic restraint and the defensive uses of migration power. In doing so, it specifies implementation, political, and reputational costs shaping decision-makers’ willingness to activate migration leverage and distinguishes among different aims in the instrumentalisation of migration, including punitive, extractive, defensive, and deterrent uses. Empirically, it applies the migration diplomacy framework to Mexico–United States relations during a period of exceptional political pressure. While migration between the two countries has been extensively studied, this specific analytical lens – focusing on migration as a tool of power politics – has rarely been employed in a Latin American context.Footnote 4
The remainder of this article is organised as follows. First, it reviews the literature on migration diplomacy and power and sets out the study’s methodological approach. Second, it outlines the proposed analytical framework. Third, it presents the case of Mexico–United States migration diplomacy during Trump’s first presidency, which was used abductively to further elaborate the theoretical construct. The article concludes with a discussion of the main findings and their implications.
Migration diplomacy and power
This study contributes to the scholarly debate on the instrumental use of migration for foreign policy purposes.Footnote 5 In particular, it analyses the relationship between transit and destination countries in the management of large-scale migration flows. These interactions have become increasingly important because of destination countries’ policies for externalising migration control. To this end, destination countries, such as the United States, the European Union, and Australia, have relied on a combination of co-optation and coercion strategies to secure the cooperation of states located along migration corridors.
Existing research indicates that transit countries, within this dynamic, actively respond to external pressures rather than remaining passive. They understand that their geographic position grants them bargaining power to defend their interests and priorities.Footnote 6 Numerous studies document cases in which transit countries secure economic, political, and security-related concessions in exchange for cooperation in migration control.Footnote 7
This body of work has consolidated into a recognisable field of enquiry known as migration diplomacy.Footnote 8 The term was first introduced by Thiollet,Footnote 9 but its formalisation is largely due to TsourapasFootnote 10 and Adamson and Tsourapas,Footnote 11 who provided a precise definition and delineated its core strategic logics. These authors defined migration diplomacy as ‘the strategic use of migration flows as a means to obtain other aims or the use of diplomatic methods to achieve goals related to migration’.Footnote 12
Within this literature, a central focus of analysis is the role of power relations between actors involved in migration governance.Footnote 13 Greenhill’s seminal work on coercive engineered migration demonstrated how population movements can serve as leverage (‘weapons’) in asymmetric state relations, anticipating dynamics later taken up by migration diplomacy studies.Footnote 14 Building on this concern with power, both Adamson and TsourapasFootnote 15 and Adamson and GreenhillFootnote 16 adopted a neo-realist–inspired perspective that emphasises how the structure of the international system – defined by the distribution of material capabilities – shapes state behaviour. From this view, a state’s position in the global migration system, whether as a destination, transit, or origin country, conditions its likely interests and the strategies available to it in migration diplomacy. This position distribution tends to correlate with the power hierarchy of the international system. Thus, more powerful states – typically destination countries – seek to block undesirable migration flows and shift the costs of migration control to other states. Transit states with less relative power tend to leverage their geographic locations to negotiate benefits that would not otherwise be forthcoming. A key contribution of this literature is its emphasis on the fact that, despite structural power asymmetries, control over human mobility creates opportunities for less powerful countries to exert influence over stronger ones.
Empirical evidence indicates, however, that such opportunities do not always translate into action. Not all transit countries – with similar geopolitical or structural positions – are willing to use migration flows as a power resource to extract benefits. Scholars have documented cases of resistance by Algeria, Mali, Indonesia, Nigeria, and Timor Leste.Footnote 17 Structural incentives help explain general patterns, yet they cannot account for the micro-level dynamics of migration diplomacy. The international structure creates a range of possibilities that either enable or constrain certain actions, but actors’ specific responses depend on their strategic calculations and how they interpret the structure.Footnote 18 Consequently, an agency-level analysis is required to explain variations in the behaviour of transit states.
Research within the migration diplomacy literature has considerably advanced our understanding of state agency in the strategic use of migration. This scholarship has explored the strategies through which states instrumentalise cross-border mobility, most notably cooperative or coercive approaches, also described as ‘backscratching’ and ‘blackmailing’.Footnote 19 It has examined when states opt for one approach over the otherFootnote 20 and under what conditions such influence attempts succeed in the context of labour migration or refugee management.Footnote 21 A variety of mechanisms have been identified – from economic and ‘hypocrisy costs’Footnote 22 to the ‘construction of deportability’Footnote 23 – that illuminate the causal pathways through which migration operates as a source of interstate leverage. However, key questions that remain under-theorised concern when and why transit countries choose to activate their migration power or refrain from doing so. Under what conditions do they opt for strategic restraint?
This article contributes to the migration diplomacy research agenda by addressing this less examined aspect of transit countries’ behaviour. It approaches this issue through an analysis of how power operates between states in concrete interactions. The article proposes a framework that disaggregates the power relationship into its constitutive elements – domain, power base, and costs – to explain how migration control functions as a source of influence in practice. The framework conceives the transit country’s decision to deploy or withhold migration leverage as a strategic cost–benefit calculation under specific structural constraints. It suggests that such strategic choices are context-dependent and shaped by actors’ interpretations of their structural environment.
Methodological note
The discussion proceeds deductively from the micro-level, agent-centred literature on power relations pioneered by Dahl and applies it to migration diplomacy.Footnote 24 This rationalist and empirically oriented tradition examines power through actors’ strategic behaviour and its observable effects. The framework also builds on earlier migration diplomacy insights, articulating them within a single analytical construct.
Empirically, the article employs a single, theory-refining case study – Mexico’s interaction with the first Trump administration (2017–21) – as a heuristic device to elaborate the cost–benefit theoretical account and nuance the framework by distinguishing between the punitive, extractive, defensive, and deterrent uses of migration power.Footnote 25 Mexico represents a paradigmatic case of a transit country in a structurally pivotal position within the world’s most intense migration corridor yet embedded in a markedly asymmetric dyad with the primary destination state. This provides a revealing setting for specifying the conditions under which transit states refrain from activating their migration leverage despite structural incentives to do so.
Process tracing is employed to reconstruct key episodes, sequences, and decisions, drawing on extensive media coverage, government press releases, memoirs, public opinion polls, official United States and Mexican data on border encounters and enforcement deployments, and budget data on the United States’ contributions to international migration organisations and Mexico’s spending on migration agencies. Mexico’s cost–benefit assessment relies on qualitative interpretation and counterfactual inference, supported by the triangulation of documentary, testimonial, and contextual evidence. It combines press reports, policy documents, public statements by key government figures, and interviews with high-ranking officials involved in decision-making. On this basis, the study reconstructs the anticipatory logic through which the Mexican government perceived potential costs.
Migration diplomacy in transit–destination country relations: Decision-making in context
Migration power as a relationship
An agency-level inquiry into power relations must rest on a specific understanding of the concept. This study adopts a relational conception of power to explain why, under comparably asymmetric structural conditions, some transit countries activate migration control as an instrument of influence while others do not.Footnote 26
In his classic definition, Dahl posited power as a social relationship in which one actor (A) gets another (B) to do something they would not otherwise do.Footnote 27 By defining power as influence, this concept moves away from the idea of power as the mere possession of resources and situates it in the context of concrete relationships, where resources are only meaningful if they succeed in affecting the behaviour of the other.
Conceiving power as a relationship entails attending to not only the resources available but also the preferences that guide actors’ behaviour.Footnote 28 This requires an understanding of the strategic context in which power is exercised. What counts as a power resource depends on the value it is expected to have within a specific relationship, according to how it is perceived by those involved.
From this perspective, power is expressed as an actor’s ability to alter the behaviour of its counterpart by introducing an element that changes the latter’s perception of costs and benefits. This ability does not reside in the resource itself but in the way it is evaluated within the relationship. Power is exercised by threatening or imposing costs or by promising or delivering benefits. The means by which A exerts influence over B are diverse: A may use financial resources (economic power), resort to its arsenal (military power), or activate resources in the realm of ideas (ideological power). In all cases, A introduces an element that has the potential to affect B’s cost–benefit perception and induce a change in its behaviour.
In this regard, when the resource employed is control over human mobility, we can speak of migration power.Footnote 29 Saltalamacchia and Urzúa defined migration power as an actor’s ability to influence another actor by affecting migration flows.Footnote 30 It is a relational phenomenon because it is actualised through interactions between agents. In itself, the ability to manipulate migration flows is not a power resource; it is simply a state attribute – something that a state does or does not possess. This capacity becomes a lever of power within the context of a particular relationship, wherein State A intentionally manipulates migration flows in a manner that State B perceives as either beneficial or detrimental to its interests, thereby prompting a change in B’s behaviour.
This relational conception of power is articulated in the work of Baldwin. Building on Dahl’s definition of power as influence, Baldwin suggested analysing its dynamics by breaking it down into elements that allow greater analytical precision.Footnote 31 His approach aimed to make the study of power more systematic and to facilitate empirical investigation. In this respect, his framework is helpful for examining how migration power operates in the concrete interactions between transit and destination countries.
The following sections draw on three key aspects of power analysis suggested by Baldwin to guide the examination of how migration power is exercised. The first is the domain, namely, who the actors in the relationship are and who can influence whom. The second is the power base, which is understood as a resource that, when strategically activated, acts as a causal mechanism within the relationship and enables successful influence attempts. The third dimension concerns the costs borne by the actors exercising power. These dimensions are complemented by a typology of purposes that guide the use of migration power. Finally, I discuss the role of structural constraints.
Domain: Who can influence whom and when
This study analyses how migration power is exercised within a specific domain: the relationship between transit and destination countries along the corridors of large-scale migration flows. Both types of states may exert migration power over each other; however, this analysis focuses on when and how transit countries do so. For transit countries to control migration and effectively translate it into a power resource, certain conditions must be met.
First, receiving societies must perceive migration flows as highly threatening or undesirable, making containment a top priority. Indeed, a transit country’s ability to contain migration becomes a source of influence only as a function of the destination country’s preferences. The greater the value destination states assign to a transit country’s control over migration flows, the greater the influence conferred upon it.Footnote 32 This implies that migration power is co-determined. It is a relational phenomenon that exists only through how both parties interact and attribute instrumental value to the capacity to control migration. Both actors actively contribute to the realisation of this power by recognising, assigning strategic value to, or acting upon it.
The second condition is that the destination country lacks effective alternatives to achieve its desired outcome, namely, containing migration. This occurs when unilateral solutions (e.g., border militarisation, physical barriers, or mass deportations) are either insufficient or significantly more costly than securing the cooperation of the transit country. Consequently, the migration power of a transit country increases or decreases as a function of the destination country’s available alternatives.
In summary, a destination country is more vulnerable to the use of migration power by a transit country when (a) it places high value on migration containment and (b) the alternatives for achieving this goal are either ineffective or more costly than inducing the transit country’s cooperation.Footnote 33 When both conditions are met, an opportunity emerges for transit countries to use migration management as a lever to extract concessions, impose or avoid costs, or deter actions that threaten their interests on the part of destination countries.
Power base or the causal logic of migration power
Any analysis of migration power must specify how its effects are exerted. Baldwin defined the power base as the ‘causal condition’ that enables a resource to produce a change in the other actor’s behaviour.Footnote 34 This notion opens the door to examining causal mechanisms, understood here as the processes through which a resource such as migration control creates incentives or imposes costs that induce the destination country to alter its behaviour.Footnote 35
A relational approach requires examining the power recipient’s perspective,Footnote 36 since its perception of costs and benefits determines how incentives translate into behavioural change. In the context of large migration corridors, the destination state’s preference to restrict migration tends to remain stable, yet its salience and implementation shift as domestic politics, institutional constraints, or public opinion pressures alter the perceived pay-offs of migration management.
As noted above, scholars have proposed different causal mechanisms to explain how migration control, as a power base, can alter a destination country’s behaviour. The literature’s contributions can be systematised around two broad logics through which migration power operates.
First, power may work through strategic rationality understood ‘as the ability to manipulate the utilities of the other through threats or promises’.Footnote 37 For example, a government that exploits migration to rally xenophobic support may exchange benefits with a transit country to reward its base. Similarly, if a powerful economic sector views mass migration as a threat to its interests, it may urge its government to make concessions to the state controlling the flows. In such cases, the power base lies in the ability to manipulate migration flows in ways that have political or economic consequences for destination countries.
Second, destination states may respond according to a normative rationality in which power works through the activation of pre-existing legal or moral obligations.Footnote 38 The principles of international law or humanitarian commitments may constrain options in the face of a migration crisis. For example, a state concerned about its prestige and norm compliance may accept another state’s demands to avoid the legitimacy costs associated with being perceived as failing to protect human rights or ignoring the suffering of migrants.Footnote 39 In this case, the power base activates a resource that generates reputational costs for the destination country.
In summary, causal mechanisms explain how migration power translates into influence. Power analysis allows for a pluralistic understanding of causality in which different types of causes interact and overlap.Footnote 40 The reasons why a destination country accepts demands or makes concessions may stem from both the ‘logic of consequences’ (economic and political considerations) and the ‘logic of appropriateness’ (ethical considerations).
Costs for the actor exercising migration power
A transit country’s decision to use migration as an instrument of influence depends on not only the destination country’s vulnerability but also the implications of such an action for the power-wielding state. In other words, what is the price paid by the actor who chooses to instrumentalise migration flows? This dimension highlights that the exercise of migration power is neither cost- nor risk-free, which may limit its use or even determine its failure.
Transit countries that exercise power by controlling migration flows face three main types of costs. First, implementation costs include budgetary and bureaucratic burdens associated with enforcing migration control measures, providing assistance to mobile populations, or integrating them socially. Second, domestic political costs result from opposition by political forces, social organisations, or public opinion. These costs include the risk of instability, especially if containment policies leave large numbers of transmigrants in the territory, potentially fuelling xenophobia and protests. Third, reputational costs occur when the instrumentalisation of migration undermines the government’s credibility or legitimacy in the eyes of relevant domestic or international actors. For instance, costs may emerge when a migration policy appears inconsistent with declared principles or political identity, or when it is perceived as compromising political autonomy.
Analysing these costs reveals that transit countries do not always choose to instrumentalise migration, even when they have the capacity to do so, because the expected benefits may not outweigh the costs associated with such a policy.Footnote 41 In summary, the cost–benefit balance captures the trade-offs shaping transit countries’ decisions to use migration control as an instrument of power and points to the limits of this strategy’s effectiveness and sustainability.
Purposes and power dynamics
Migration power manifests when a transit country uses its capacity to control migration flows as a strategic resource in its interaction with a destination country. Yet exercising this capacity may serve different ends. Focusing on the purposes of action allows for a more nuanced understanding of when and how transit countries deploy their migration leverage. These purposes are associated with the type of power dynamic at play, which can be either unilateral or reciprocal.Footnote 42
In a unilateral power situation, one actor (A) is positioned to independently determine the sanctions it will impose on another actor (B), without the latter having any real ability to influence these decisions. There is no room for mutual accommodation. In the context of migration power, this dynamic can be observed, for example, when the transit country decides unilaterally to relax migration controls – or even encourage flows – to inflict costs on the destination country without bargaining.Footnote 43 This is a punitive purpose.
More common are reciprocal power dynamics, that is, situations in which ‘not only can A exert pressure on B in order to get him to adopt certain specific policies, but B can do the same to A’.Footnote 44 In other words, both actors have leverage in their interaction, although to different degrees. Strategic negotiations are the clearest manifestations of reciprocal power.
In this context, the transit country may use migration containment for extractive purposes, that is, to obtain concessions from the destination country such as market access or military assistance.Footnote 45 Transit countries can pursue this objective when the opportunity costs of non-cooperation (abandoning the negotiation) are higher for the destination country than for themselves. In such circumstances, they are positioned to demand compensation in exchange for migration management.
Alternatively, migration power may be used in a bargaining setting for defensive purposes, that is, to avoid or mitigate costs that the destination country has imposed or is threatening to impose, such as economic sanctions. The transit country does not claim rewards but leverages its position to shape the terms of cooperation and reduce its burdens.Footnote 46 We expect this to happen when the opportunity costs of a breakdown in negotiations are higher for the transit country than for the destination country. The former’s main concern is to avoid failure, prompting caution rather than the pursuit of further gains.
Within reciprocal power dynamics, where both actors adjust their behaviour based on the possible reactions of the other, transit countries may also use migration management with a deterrent purpose, that is, to prevent the destination country from taking hostile measures against them.Footnote 47 In international relations, deterrence consists of persuading a potential aggressor that the risks and costs of action outweigh the expected gains, thereby discouraging the intended action.Footnote 48 The literature identifies two forms of deterrence: by punishment and by denial.
In the context of migration power, deterrence by punishment occurs when the transit country threatens to withdraw migration cooperation to persuade the destination country to reconsider a hostile action. Alternatively, deterrence by denial refers to ‘the capability to deny the other party any gains from the move which is to be deterred’.Footnote 49 In the latter case, the deterring country takes steps to de-legitimise the hostile action and ensure that it cannot be translated into a political victory.Footnote 50 For instance, this happens when the transit country pre-emptively enforces migration control in a manner that prevents the destination country’s government from gaining any advantage through the imposition of sanctions aimed at compelling cooperation in migration. The essence of this strategy is to ensure that aggression becomes politically useless, thereby eliminating both the incentives and justifications for its implementation.
Migration power of transit countries within asymmetric structures
In addressing the questions of when and how transit countries exercise migration power, the analysis so far has focused on state agency and the dynamics of interstate interaction. Yet agency does not unfold in a vacuum: states act within structural contexts that shape the range of possibilities within which decision-makers interpret their room for manoeuvre and make strategic choices. In this sense, agency is situated: it is exercised in concrete interactions while being conditioned by structural configurations that enable and constrain actors’ options.Footnote 51 Understanding migration power as a form of situated agency provides a means of integrating the structural and agential levels of analysis within the migration diplomacy research programme.
Scholarship on this field has highlighted that such diplomatic practices commonly unfold within asymmetric international structures that favour destination countries. These states tend to occupy positions from which they can define regulatory priorities, set the terms of cooperation, and embed migration governance within broader institutional and normative arrangements that reflect their preferences. In other words, they hold structural power.Footnote 52
Transit countries, by contrast, may exercise migration power through flow control and border management; however, they do so within a context structured by institutional settings and incentives largely shaped by their counterparts. In this framework, migration control functions as a tactical and contingent tool of influence, whose activation depends on specific political junctures. This is relational power, expressed through concrete interactions yet constrained by the broader asymmetry that frames them. It rarely alters the underlying hierarchy but allows transit states to navigate it strategically.
Both ‘agents and structures are indispensable to any adequate social explanation’ and their relative influence ‘cannot be settled theoretically’ but must be established empirically.Footnote 53 Methodologically, researchers can explore how structural and agential dimensions interact in concrete instances of interstate negotiation.Footnote 54 The next section examines the Mexico–United States interactions in light of the proposed framework.
Migration and power politics in Mexico–United States relations
Domain configuration and causal condition: Threat perception and political pressure in the United States
Donald Trump won the presidential election in 2016 with a campaign centred on stoking fear about immigration. His rhetoric portrayed migrants as a threat to the personal safety of citizens and jobs of American workers. He accused the Democrats of pursuing an ‘open borders’ policy and neglecting the interests of native-born Americans. He pledged to deport millions of undocumented migrants and complete the wall along the border with Mexico. Throughout his presidency, migration remained a priority issue. Trump issued an unprecedented 472 executive orders related to migration policy and visited the border region seven times.Footnote 55
For the first year and a half, the Trump administration focused on implementing interior enforcement measures. To increase arrests and removal, the administration made all undocumented immigrants subject to deportation. Immigration checks were also stepped up at workplaces and on trains and buses near the border.Footnote 56 At the same time, Trump pushed for congressional approval to fund the expansion of the border wall. These domestic actions proved less effective than expected. Mass deportations were hampered by a lack of cooperation from state and local authorities with the United States Immigration and Customs Enforcement, particularly in cities with sanctuary policies.Footnote 57 Congress allocated limited funding to the wall, mostly for the maintenance of already built sections.Footnote 58
Regarding the Mexico–United States border, by the end of 2017, encounters with undocumented migrants had decreased by 43 per cent because of the deterrent effect of Trump’s anti-immigration rhetoric. Migrants and human smugglers adopted a ‘wait and see’ attitude. However, in the spring of 2018, flows began to rise again, prompting Trump to intensify border control efforts through a ‘zero tolerance’ policy and family separation. This, in turn, contributed to the emergence of a new phenomenon: migrant caravans – groups of hundreds or even thousands of people travelling together to increase safety, visibility, and mutual support.
In 2018, five caravans departed from Mexico, Honduras, and El Salvador for the United States.Footnote 59 They received significant media attention, partly because Trump – who was facing mid-term congressional elections – described them as ‘an invasion of our country’.Footnote 60 In November, he ordered another unilateral action: the deployment of troops to the Tijuana–Mexicali border region.
However, by the end of 2018, encounters at the southern border of the United States had nearly returned to 2016 levels, and in early 2019, monthly records reached historic highs (Figure 1). Between January and June 2019, four additional caravans originating in Honduras were recorded. Clearly, the Trump administration was unable to achieve its objectives through unilateral actions alone. This called into question the president’s credibility and generated mounting public pressure.Footnote 61 In response, the administration shifted its strategy towards externalising migration control and sought Mexico’s cooperation.

Figure 1. Encounters at the United States–Mexico border (2017–20).
Thus, the perception of a migration crisis in the United States fuelled by Trump and the limited effectiveness of his unilateral measures created a window of opportunity for Mexico as a transit country to hold potential migration power. The Mexican government’s response to this political juncture reveals how this potential translated into concrete forms of influence.
Interactions between Mexico and the United States
From May 2018 onwards, the Trump administration, guided by the logic of consequences, opened up clear opportunities for Mexico to use migration management as a bargaining chip in its bilateral relationship. First, the United States government held discreet talks with the outgoing Enrique Peña Nieto administration to negotiate a Safe Third Country Agreement (STCA), which reportedly offered significant economic incentives in exchange for Mexico’s acceptance.Footnote 62 Such an agreement would make all transmigrants who had not first applied for protection in Mexico, and were rejected, ineligible for asylum in the United States. However, as Peña Nieto’s presidency was coming to an end, it was politically unfeasible for him to make decisions of this magnitude.
The second attempt came after the presidential election on 1 July in which Andrés Manuel López Obrador (AMLO) was elected with 53 per cent of the vote. The Trump administration offered to transfer US$20 million to Mexico to fund an immediate increase in deportations from its territory.Footnote 63 The outgoing government stated that it was evaluating the proposal but ultimately did not accept it.Footnote 64 The president-elect’s political team openly rejected the offer.Footnote 65
Even before the new administration took office on 1 December 2018, the Trump administration made another attempt to align the incoming Mexican government with its migration containment goals. In a private meeting, Secretary of State Mike Pompeo offered Marcelo Ebrard, Mexico’s designated foreign minister, an explicit quid pro quo: the bilateral relationship, he said, ‘is going to be very simple. If the border numbers go up, there will be problems. If they go down, the United States will be an incredible partner and will help Mexico with its priorities.’Footnote 66
The new government rejected this transactional approach. In his inauguration speech, AMLO outlined a regional development-based strategy to address the root causes of migration and proposed an investment agreement between Mexico and the United States to promote growth in Central America. He stated that he sought ‘to address the migration phenomenon in this way and not through coercive measures’.Footnote 67 He also agreed with the governments of Guatemala, Honduras, and El Salvador to task the Economic Commission for Latin America and the Caribbean with formulating a Comprehensive Development Plan to address the origin of migration. Finally, he appointed a prominent academic to head Mexico’s National Migration Institute (NMI), whose migration paradigm stood in stark contrast to the punitive policies promoted by Trump.
Frustrated by Mexico’s position, the Trump administration resorted to an exercise of unilateral power: it implemented a measure known as the Migrant Protection Protocols or ‘Remain in Mexico’. The directive stipulated that individuals arriving at the border to seek asylum in the United States would be returned to Mexico and required to remain there while their cases were processed in US immigration courts. In a private meeting in late 2018, Pompeo warned Ebrard that if Mexico refused to accept these migrants, the United States would shut down the border.Footnote 68 Under pressure, the Mexican government accepted the measure but publicly framed it as a unilateral US decision with which Mexico agreed to cooperate solely on humanitarian grounds.
‘Remain in Mexico’ began operating in certain border areas in January 2019. In practice, this imposed a significant burden on Mexico, which was unprepared to accommodate thousands of expelled migrants. This tightening of migration pressure coincided with another crucial bargaining front, the renegotiation of the North American Free Trade Agreement initiated by the Trump administration. Migration-related discussions thus unfolded within a particularly delicate structural environment in which the United States not only exerted direct pressure on this issue but also controlled the timing and conditions of an agreement central to Mexico’s economy.
Despite threats from the United States, the Mexican government did not budge from its original position. The Ministry of the Interior remained steadfast in implementing a human rights–based migration policy. It responded by issuing thousands of humanitarian visas that allowed migrants to stay in the country for one year and work legally as well as offering them the opportunity to apply for refugee status in Mexico. However, many migrants continued their journey northward, and in May 2019, encounters with undocumented migrants at the border peaked at 144,116 – the highest monthly figure in the decade.
On 30 May 2019, Trump issued a public threat to Mexico: as of 10 June the United States would impose a 5 per cent tariff on all goods imported from Mexico, which would gradually increase until the Mexican government succeeded in stopping the northward flow of migration. In principle, this threat was another act of unilateral power with no initial room for compromise. In response, AMLO sent a Mexican delegation led by Ebrard to Washington, DC, to begin a negotiation process. On 7 June, after three rounds of discussions, both sides announced a political agreement.Footnote 69
The United States’ opening position was the immediate signing of a STCA.Footnote 70 Despite acute pressure, Mexico avoided this commitment, which was considered costly because of its binding and permanent nature. Instead, Mexico agreed to intensify migration control by deploying Armed Forces along its borders.Footnote 71 In addition, Mexico committed to expanding the implementation of the ‘Remain in Mexico’ programme. The United States offered some concessions – it agreed to accelerate the processing of asylum applications to reduce the waiting times for migrants. A reference to joint efforts in the development of Central America was also included as a symbolic element through which Mexico sought to frame the agreement as part of a shared responsibility strategy for managing migration to the region. A period of ninety days was designated for the evaluation of the results.
This scenario tested Mexico’s ability to operate within an asymmetric international structure. Mexico manoeuvred to transform an act of unilateral power into a strategic negotiation characterised by a dynamic of reciprocal, albeit unequal, power. It was a reactive position as Mexico adjusted its conduct in response to the threat but managed to retain a degree of agency by shaping the nature of the concessions. This room for manoeuvring stemmed from the United States perceiving Mexico’s immediate cooperation in containing migration as a critical necessity. Mexico leveraged its influence, or migration power, as a transit country to avoid two major costs: the imposition of tariffs and the formalisation of a STCA.
On 10 September 2019, Ebrard met Trump in the White House to review the results. Indeed, encounters with undocumented migrants at the border had decreased by 56 per cent (Figure 1). The following day Trump acknowledged that Mexico was delivering on the agreement and the issue of tariffs was set aside.Footnote 72
As a result of this bilateral dynamic, migration policy came to be regarded as a matter of national security and foreign policy in Mexico. In September 2019, a presidential decree established the Interministerial Commission for Comprehensive Migration Affairs to coordinate the actions of different agencies in managing migration flows. Although migration was the responsibility of the Ministry of the Interior, it was decided that the Ministry of Foreign Affairs (MFA) would lead it. This represented an implicit recognition that migration policy would henceforth be shaped by not only domestic considerations but also international commitments and external pressures. At the initiative of the United States, migration policy became a key instrument of influence and negotiation within the bilateral relationship.
Throughout the remainder of the Trump administration, Mexico continued to deploy its armed forces in an effort to curb transmigration. Between September 2019 and September 2020, border encounters were relatively low. Trump left open the possibility of demanding a STCA. Moreover, in the second half of 2019, the process of finalising the new trade agreement continued, and by December it was pending ratification by the US Congress. The Mexican government understood that the migration card was a resource to neutralise Trump’s hostility and could even be leveraged to promote a more fluid bilateral relationship.
Formal negotiations were forsaken after the open transactional diplomacy phase. Mexico shifted towards deterrence by denial, that is, maintaining migration control with the aim of nullifying political arguments and incentives that might generate future pressure from the United States. By the end of Trump’s presidency, Mexico had succeeded in avoiding the STCA, which was imposed on Guatemala, Honduras, and El Salvador between July and September 2019. The trade agreement was ratified and enacted in July 2020.
Strategic assessment of the transit country
As discussed above, between 2018 and mid-2019, Mexico declined to enter negotiations with the United States to secure benefits in exchange for aggressively containing migration flows. The government was reluctant to use Mexico’s position as a transit country as a power resource to influence Trump’s behaviour. This can be explained by the cost–benefit assessment involved in such a transactional dynamic.
Migration was central to AMLO’s electoral campaign and one issue through which he sought to differentiate himself from previous administrations.Footnote 73 He pledged to prioritise human rights and development over coercion. This approach was enshrined in the National Development Plan and officially launched during the first month of his administration.Footnote 74 Given these commitments, the government could anticipate political costs if it were to change course and adopt a repressive migration policy. Such a reversal would have emboldened opponents and risked alienating part of the government’s own support base, who identified the administration with defending vulnerable groups.Footnote 75 The backlash that followed subsequent measures of migration enforcement – criticised by legislators from AMLO’s own partyFootnote 76 and opposition Footnote figures 77 – illustrated the political risks the government could reasonably expect from the outset.
Reputational costs were also anticipated, both domestic and international. Domestically, they were tied to the notion of political independence. Yielding to foreign pressure – particularly from a government hostile to Mexican migrants – was seen as undermining Mexico’s autonomy. AMLO’s rhetoric consistently reaffirmed the principles of sovereignty and non-intervention, rejecting the idea of Mexico acting as the United States’ migration enforcer.Footnote 78 Officials framed this as a sovereignty cost: the INM Commissioner cautioned that Mexico’s migration policy ‘could not be subordinated to the electoral interests of the United States’,Footnote 79 while the Undersecretary of the Interior emphasised the need to preserve ‘autonomy’.Footnote 80 The Senate likewise insisted that Mexico’s migration policy ‘must remain an exercise of sovereignty, not the product of external pressure or lobbying’.Footnote 81 Accepting a STCA was therefore perceived as contradicting nationalist principlesFootnote 82 and exposing the administration to criticism for failing to defend Mexican interests.
Internationally, similar reputational risks were foreseen. Endorsing an agreement that used migrants as a bargaining tool was perceived among diplomats as jeopardising Mexico’s legitimacy to safeguard the rights of its citizens abroad. As a country of emigration, Mexico had historically demanded dignified treatment for its nationals. AMLO himself had warned that inconsistencies in this regard would ‘demolish our moral authority to defend our fellow countrymen north of the Río Bravo’.Footnote 83 Members of the Mexican Foreign Service – particularly those versed in migration diplomacy – believed that agreeing to stringent containment or an STCA would harm Mexico’s international prestige. They viewed excessive concessions to Washington as setting an undesirable precedent and weakening the country’s credibility as a consistent advocate for migrants’ rights.Footnote 84
Finally, implementation costs loomed large. Government officials were aware that Mexico lacked the material and administrative capacities to achieve the level of containment sought by the United States or to handle a massive influx of asylum applications.Footnote 85 As later became evident, implementing such policies required substantial institutional and budgetary adjustments that the government was not prepared to undertake at the time.
However, Trump’s ultimatum in May 2019 marked a turning point in Mexico’s position, forcing it to recalculate costs and benefits. A bilateral trade war would have been catastrophic, given that 77.8 per cent of Mexico’s exports went to the United States, and imports from that country accounted for 45.2 per cent of the total.Footnote 86 Internal estimates by the Ministry of Economy suggested that tariffs could wipe out ‘around two million jobs’ and ‘push people onto the streets’, further fuelling migration pressures.Footnote 87 The government also anticipated that this scenario would effectively nullify the free trade agreement – a long-term consequence.Footnote 88 Moreover, a direct confrontation with the Trump administration carried risks in other areas of the bilateral relationship. Mexico was compelled to carefully consider the systemic implications of migration-related decisions in a context of asymmetrical interdependence.
The cost of mass unemployment was perceived as significantly higher than the cost of tightening migration policy.Footnote 89 Consequently, the government implemented the Northern and Southern Border Migration and Development Plan, which relied on an unprecedented and large-scale deployment of Mexico’s Armed Forces to detain undocumented transit migrants. In 6 June 2019, 6,500 troops were assigned to the southern border and 15,000 to the northern border,Footnote 90 representing approximately 6.6 per cent of total military personnel.Footnote 91 Following this initial deployment, a militarised migration control plan remained in place for the rest of the term (Table 1). This was consistent with the logic of deterrence by denial.
Table 1. Deployment of SEDENA and National Guard personnel under the migration containment plan (2018–24).1

1 This refers to the ‘Migration and Development Plan at Mexico’s Northern and Southern Borders’.
2 Secretaría de la Defensa Nacional (SEDENA), ‘First Activity Report, 2018–2019’,(2019).
3 For all subsequent periods: Second to Sixth Annual Reports of the President to Congress.
The AMLO administration sought to mitigate the political and reputational costs of the agreement with the United States by manipulating its meaning. In the president’s daily press conferences, migration control was framed as a policy aimed at protecting migrants and as a matter of national self-interest. As evidenced by a discourse analysis, the president employed euphemisms to obscure the punitive dimension of containment and legitimise it before a domestic audience. For example, detentions were referred to as ‘rescues’ of migrants, and deportations were described as ‘return of persons’ or ‘assisted return’. Bilateral tensions and commitments made to the United States were downplayed to emphasise that the containment plan was merely the enforcement of Mexico’s national migration law and an action against criminal human smuggling networks. Simultaneously, AMLO consistently reminded the public that Mexico was addressing the social dimension of migration through development cooperation with Central American countries. He maintained an affectionate tone when referring to migrants (‘our Central American brothers’) and urged the Mexican public to reject xenophobia.Footnote 92
Criticism from opposition parties and civil society organisations focused on human rights violations against transmigrants, the militarisation of migration containment, and the government’s alignment with an American president who mistreated Mexican nationals. Nonetheless, the president’s rhetorical framing appeared effective. Opinion polls showed majority support for migration control, deportation of transit migrants, and the use of the Armed Forces in these tasks.Footnote 93 In this context, the continuation of aggressive migration control – and, with it, the pursuit of deterrence by denial after the critical juncture of 2019 – proved to be politically viable.
In its interaction with the United States, Mexico’s primary objective was to minimise relative costs. Unlike other transit countries, such as Turkey and Libya, it did not seek direct financial compensation for acute migration enforcement. Interviews suggest two explanations for this stance. Two officials emphasised the reputational costs that demanding side payments would have entailed, noting that such a move would have undermined the Mexican government’s humanist discourse and the image of a sovereign state guided by principles rather than transactions.Footnote 94 Others interpreted Mexico’s cautious approach as a response to asymmetry in the negotiating context, recognising that the opportunity costs of a breakdown in negotiations were considerably higher for Mexico than for the United States.Footnote 95 This perception reflected a situated awareness of constraint: decision-makers internalised the imbalance and opted for a defensive use of migration power aimed at avoiding escalation rather than extracting rewards.
Nevertheless, there were indications that Mexico obtained indirect benefits from its subsequent deterrent stance. Following the June 2019 migration agreement, the United States began directly funding the operations of the International Organisation for Migration (IOM) and United Nations High Commissioner for Refugees (UNHCR) in Mexico. This multilateral channel avoided political scrutiny while strengthening the operational capacity on the ground. During the first two years of the Trump administration, no humanitarian funding was allocated to its southern neighbour. In contrast, the IOM received US$1.4 million and US$21 million in 2019 and 2020, respectively, to support migrant services and the voluntary return of migrants in Mexico.Footnote 96
For its part, UNHCR’s operational expenditure in Mexico quadrupled between 2017 and 2020, rising from US$9.6 million to US$40.4 million, financed almost entirely through voluntary contributions from the United States in the last two years of the period.Footnote 97 This helped to reduce the financial burden on the Mexican state, whose expenditure in the areas of ‘migration policy and services’ and ‘assistance to refugees in the country’, managed by the NMI and the Mexican Commission for Refugee Assistance, remained relatively stable at an average of US$240 million per year between 2017 and 2020.Footnote 98
The AMLO government seemed to obtain reciprocity in other political aspects of the bilateral relationship. First, Trump’s anti-Mexican rhetoric subsided. For instance, a review of his posts on the social media platform X shows that from June 2019 onwards, he ceased attacking Mexico.Footnote 99 Several gestures of goodwill followed. For instance, in April 2020, Trump intervened on Mexico’s behalf within the OPEC+ framework by assuming a production cut of 250,000 barrels per day to unblock the negotiations. This move saved Petróleos Mexicanos (PEMEX) from a more significant production cut and was presented by AMLO as a diplomatic victory.Footnote 100
Similarly, at the height of the COVID-19 pandemic, AMLO requested Trump’s assistance in facilitating the sale of ventilators to Mexico amid a global shortage. Trump granted the request, ensuring a shipment from American suppliers.Footnote 101 In October 2020, the Drug Enforcement Agency arrested Mexico’s former Minister of Defence, Salvador Cienfuegos, for drug trafficking charges. One month later, the Department of Justice unexpectedly dropped the charges and returned him to Mexico. Security experts have linked this unusual decision to Mexico’s cooperation on migration issues.Footnote 102 Taken together, these developments suggest that migration control served as a real, albeit limited, source of influence insofar as the United States recognised its strategic value and adjusted its stance towards Mexico.
In summary, despite its initial reluctance, Mexico was induced by the United States to adopt a transactional stance on migration. During the negotiations, it defensively used its migration power to minimise costs and condition concessions. Subsequently, it maintained migration control to deter future pressure within a structurally asymmetric bilateral relationship. Migration was not used as a bargaining chip to extract explicit side benefits but rather as a tactical tool to preserve a degree of autonomy in an adverse context.
Conclusions
This study built on the migration diplomacy approach to analyse how transit countries use migration as a power resource in their strategic interactions with destination states. It developed an analytical framework that draws on the structural insight that states’ behaviour is shaped by their position within the global migration system while integrating an agency-centred perspective to explain variation in the conduct of transit countries. In particular, the study examined how transit states assess the costs and benefits of activating or withholding their migration leverage, conceiving this calculation as situated within specific relational and structural contexts.
The framework was applied to Mexico–United States relations during the first Trump administration and demonstrates that a transit country with potential migration power – stemming from its geographical location and the vulnerability of the destination state – may choose not to exercise it, or to turn it into a defensive or deterrent tool. The case functions heuristically to refine the framework and show its capacity to account for different strategic choices made under asymmetric conditions.
During the study period, Mexico found itself in a favourable position to exercise migration power, given the political centrality that Trump attached to containing flows and the limited effectiveness of his unilateral measures. The domestic pressure stemming from his promise to drastically reduce immigration led him to seek an arrangement with Mexico in line with the logic of consequences. However, the Mexican government was initially reluctant to use migration management as an instrument to influence bilateral interactions. Despite the United States offering incentives and proposing a transactional relationship, the Mexican government rejected this dynamic and advanced an approach based on economic development and respect for human rights. This position reflected an assessment of the political, reputational, and implementation costs involved in instrumentalising migration as a power resource.
The tariff threat issued in May 2019 altered Mexico’s cost–benefit equation. Faced with the risk of an economic crisis, the Mexican government entered into transactional diplomacy, not because it recognised value in instrumentalising migration, but because the opportunity cost of not doing so was perceived as prohibitive. Mexico employed its migration power – that is, its margin of influence – for defensive purposes: to reduce costs and shape the nature of the concessions agreed upon within a dynamic of reciprocal yet unequal power.
Later, Mexico employed its migration power under the logic of deterrence by denial, with the aim of pre-empting further coercion. Over time, this approach seemed to generate indirect benefits within the bilateral relationship. These benefits were not the result of explicit negotiations but stemmed from the stabilising effects of sustained migration control, through which Mexico fostered goodwill and reduced incentives for renewed pressure.
Theoretically, the study makes three contributions. First, it brings to light forms of transit state practice that are less visible in the literature, most notably strategic restraint and the defensive and deterrent uses of migration power that complement the more familiar punitive and extractive purposes. Second, it highlights the importance of accounting for the costs borne by the power-wielder itself – political, reputational, and implementation costs – that shape whether migration power is exercised. By shifting attention to these internal constraints, the framework advances our understanding of why transit countries with potential leverage may refrain from activating it.
Third, the analysis highlights the inherent limitations of the migration power of transit countries within asymmetric international structures. It suggests that this is a contingent form of power that emerges in specific conjunctures and operates within the confines of discrete interactions. Although transit countries may obtain benefits or avoid costs in particular negotiations, their control over migration flows does not grant them the capacity to alter the structural dynamics of the relationship. The ability of destination countries to mobilise other resources, set priorities, and control institutional frameworks – for instance, by forcing the renegotiation of a trade agreement and defining the legitimate terms of cooperation (as in linking migration and trade) – reflects a form of structural power that constrains, yet does not eliminate, the margin of influence available to transit countries.
Finally, the framework also underscores that migration power is co-determined. It cannot be understood without considering how the destination country frames migration as a threat and seeks to externalise its management. Recognising this co-determination helps to make visible the destination countries’ co-responsibility in what is often denounced as the commodification of migrants’ lives by transit countries or refugee rent-seeking. This point, also noted by Tolay,Footnote 103 is theoretically grounded in the relational notion of power. In this sense, the relational approach serves as a critical tool. It compels us to question not only transit states but also receiving states, which actively shape the conditions under which such instrumentalisation occurs.
Video Abstract
To view the online video abstract, please visit: https://doi.org/10.1017/S0260210526101831.
Acknowledgements
I am grateful to the editors of RIS and the anonymous reviewers for their incisive engagement and constructive suggestions. I also thank María José Urzúa, with whom I first began studying migration power, for the intellectual exchange that shaped my interest in this line of research. Many thanks as well to Pablo Kalmanovitz and Carlos Heredia for their thoughtful feedback on previous drafts.