Thirty-five years ago, Joseph Carens published “Aliens and Citizens: The Case for Open Borders” in the Review of Politics.Footnote ¹ It is only a slight overstatement to say that this article created the subfield of political theory of migration.Footnote ² Today, the field is flourishing. Migration continues to be one of today's most politically fraught and morally urgent issues. An estimated hundred million people have fled violence and persecution.Footnote ³ Hundreds of millions more cross international borders every year.Footnote ⁴ States have responded with highly restrictive policies, in which people need to resort to perilous routes, often in the hands of smugglers, to claim asylum.

Attention to migration encourages us to reconsider our views about freedom, authority, democracy, community, and much else. This review essay takes stock of the state of the field and speculates on its future. I highlight three themes. First, as the field has expanded, theorists come to migration from different methodological stances. While liberalism, broadly construed, continues to be the dominant framework, theorists increasingly find resources in feminist thought and philosophy of race. Second, normative theorists now engage much more deeply with the empirical literature, in some cases combining fieldwork and normative theory. This has led to a shift from broad questions about the morality and legitimacy of border controls to more specific issues such as the ethics of refugee camps and repatriation, the realities of immigration enforcement and surveillance regimes, and the role of race and racialization in immigration policy, as well as challenges specific to particular geographical regions. Third, migration raises broader issues of political theory, challenging us to reimagine political and social boundaries for a mobile world.

Gillian Brock traces the principal debates in the field in her valuable overview, Migration and Political Theory. Interventions in the first three decades of the political theory of migration roughly divide into questions about the admission of immigrants and debates about obligations to people already present.Footnote ⁵ Questions of admission centered around open borders and the justifications (if any) for states to exclude immigrants. Refugees received special attention, with most theorists agreeing that they have an especially strong claim to admission (20–43).Footnote ⁶ This led to discussion around the moral adequacy of the definition of refugee set out in the 1951 Convention Related to the Status of Refugees.Footnote ⁷ While emigration has received less attention that immigration,Footnote ⁸ there is a also robust subliterature around the emigration of skilled workers (commonly referred to as “brain drain”) (157–78).Footnote ⁹

Another prominent topic concerns immigrants without the legal right to reside, either because they entered the territory irregularly or because their status changed (e.g., by overstaying a visa) (120–39). What obligations do states have to these immigrants, many of whom have lived, worked, and raised families in the territory for years or even decades?Footnote ¹⁰ What rights need to be respected? Are states required to provide a pathway to legalization?Footnote ¹¹

Another set of questions revolve around obligations to people admitted on a temporary basis (149–56). Many countries have temporary-worker programs that impose limits on how long workers can stay, who they can work for, what rights they can exercise, and whether they can change their status to permanent residence.Footnote ¹² These programs are often exploitative and render migrants vulnerable to physical and sexual abuse. In some cases, temporary workers are subjected to indentured servitude. But even in cases where states guarantee temporary workers’ labor and civil rights, these programs are founded on workers’ unequal status. Can a just society permit the persistence of groups of people who are systematically denied full rights? Do they need to extend a pathway to permanent status and citizenship? When there is a pathway to citizenship, is it permissible for states to impose language requirements and citizenship tests?Footnote ¹³

In recent years, theorists have begun to take more seriously the realities of immigration enforcement and its implications for migration justice (181–85).Footnote ¹⁴ Immigration enforcement includes practices of border externalization, in which affluent states co-opt sending and transit states into preventing migrants—including refugees—from reaching their territory.Footnote ¹⁵ Australia's system of offshore detention is one of the more notorious examples,Footnote ¹⁶ but, as Chandran Kukathas emphasizes in Immigration and Freedom, it is part of a broader “carceral archipelago” (240). States have also normalized immigrant detention, including detaining people (including children) who have exercised their legal right to claim asylum. Immigrant detention falls under administrative law and is allegedly nonpunitive, so immigrants often have fewer legal protections than people accused of serious crimes.Footnote ¹⁷ This raises questions about the justice of resisting unjust policies, whether it is illegally crossing a border, assisting migrants in crossing, or protesting authorities through direct action (Brock 185–89).Footnote ¹⁸

The seven books under review all extend these debates in important ways. In “Aliens and Citizens: The Case for Open Borders,” Carens made a compelling case that utilitarianism, Rawlsian egalitarianism, and libertarianism all support open borders. Chandran Kukathas's Immigration and Freedom could be described as a sophisticated, empirically informed extension of the implications of libertarianism for border controls, bringing together Robert Nozick and Frederick Hayek with Alexis de Tocqueville and Michel Foucault. I will focus on three themes in Kukathas's book: the question of who is an immigrant, what a commitment to freedom means for immigration policy, and his criticisms of nationality.Footnote ¹⁹

The category of “immigrant” is vague, contested, and morally urgent. People often fit into multiple categories (e.g., it is possible to simultaneously be a student, worker, family member, and a refugee) and their situation can change.Footnote ²⁰ This becomes even more fraught when we recognize that “immigrant” is also a social category. In the United States, native-born people of Asian, Latinx, or African descent are too often treated as foreigners, while white Canadians may be treated as citizens. The category of native is in no respects clearer. Kukathas reviews twenty possible definitions of “native,” demonstrating how holding citizenship and being born in a country do not necessarily mean a person will be considered a native (20–23).Footnote ²¹

Legal and social categories affect not only the ability to cross borders and take up residence, but the whole range of civil, social, and economic rights. These categories are sustained by surveillance and enforcement regimes. Many of our institutions are co-opted into verifying people's legal status, including workplaces, housing, schools, and banks. It is impossible to control immigration without imposing controls on everyone else, including through the racial profiling of people associated with immigrant groups.Footnote ²²

For Kukathas, the greatest danger of immigration controls is their threat to a free society. We have not only normalized detention, but also surveillance. Immigrants and citizens alike docilely allow immigration authorities to compare our biometrics against vast databases.Footnote ²³ Submitting to immigration enforcement does more than limit people's opportunities; it teaches them to become complacent toward living in a less free society (251).

Immigration and Freedom radically critiques nationality. Immigration controls are frequently justified as the will of a people united by common political membership, culture, history, and identity exercising self-determination. Kukathas argues that this ideal of self-determination rests on an untenable conception of political community and fails to withstand scrutiny into how political decisions are actually made. It relies on fanciful national-building stories that political elites use to construct a shared identity, build legitimacy, and exercise control over populations. Moreover, self-determination exercised in “our” name provides a pat and problematic answer to the question of who is an immigrant and who is a native, obscuring how decisions that benefit some dominate others.

Our next book, Molly Gerver's The Ethics and Practice of Refugee Repatriation, combines the skills of a qualitative researcher with the rigor of an analytic philosopher. Voluntary repatriation is one of the United Nations High Commissioner on Refugee's three “durable solutions” (the other two are local integration in the country of asylum and resettlement to a third country). Voluntary repatriation is contrasted with deportation; as the name suggests, “voluntary repatriation” is supposed to be voluntary, whereas deportation is by definition coerced. But, as Gerver's deft fieldwork illustrates, the reality is much more nuanced.Footnote ²⁴ Refugees may choose to repatriate because the alternative is detention, discrimination, or a precarious struggle to survive without the legal right to work or receive public services. They may be basing their decisions on false information that undermines their ability to assess the risks. Governments also pay refugees to repatriate, raising delicate questions about the use of incentives to encourage choices that could lead to death or destitution. Children raise further complications about risk, parental rights, and the best interests of minors.

Most work in the philosophy of migration has focused on state injustice. This is a major oversight since governments have outsourced immigration regulation and enforcement to the private sector and support services to not-for-profit organizations.Footnote ²⁵ Refugee resettlement in particular has long been accomplished through partnership with community-based organizations (including religious groups). Not-for-profit organizations often operate under conditions of injustice and find themselves in circumstances such as trying to ethically assist with repatriation when the alternative is detention. Gerver's analysis provides tools for thinking through these dilemmas.

Amy Reed-Sandoval also draws on ethnographic research in Socially Undocumented, interviewing pregnant women and medical professionals about their experiences seeking medical care across the US-Mexico border. Pregnant border crossing is legal, but it takes places against the background of racist propaganda about Latina fertility, tied to the white supremacist “great replacement theory” and ugly conspiracies about “anchor babies.”Footnote ²⁶ As a result, pregnant women are often subjected to hostile scrutiny from officials. Reproductive justice for migrant women is increasingly urgent after Dobbs v. Jackson Women's Health Organization overturned Roe v. Wade, further limiting already precarious access to abortion.Footnote ²⁷

Reed-Sandoval's fieldwork buttresses her thesis about how people can be “socially undocumented,” especially because of anti-Latinx racism in the United States. Many people possess legal status, but are nonetheless treated as if they do not have the right to cross a border or are illegally present in a territory. This treatment is based on perceptions of race, class, and gender. Indeed, racial profiling at the US-Mexico border (which, by law, extends one hundred miles into the interior) is broadly permitted under US Constitutional law. Socially undocumented immigrants are caught in a double bind, in which all of their limited choices are penalized or subject to censure. For example, their survival may depend on accepting dirty, dangerous, and demeaning work; in turn, carrying out this work contributes to their identification as “undocumented” immigrants and subjects them to oppressive immigration controls (Reed-Sandoval, 130). Notably, “social documentation” can have little or no connection to legal status; the border patrol's discriminatory treatment of Indigenous peoples such as the Tohono O'odham on the Mexico-US border parallels its treatment of migrants.

Socially Undocumented is usefully read in conjunction with Allison B. Wolf's Just Immigration in the Americas. Wolf also draws our attention to how injustice arises through the gendering of migration. Women have always migrated, with their choices and opportunities structured by patriarchal gender roles. These determine legal paths for immigration, for example, through temporary visas for work in feminized labor sectors or through family-based immigration policies. Immigration policies often place women in positions of systematic vulnerability, more likely to suffer rape and sexual assault on the migration journey or in the workplace (which, in the case of care work, may be the employer's home). Transgender women face special challenges in the asylum process and in immigrant detention.Footnote ²⁸

Wolf emphasizes how the migration of women and children led to the family separation policy and that this is an instance of reproductive injustice (101). Her chapter “‘Nosotras no valemos nada acá en Colombia’ [We are worth nothing in Colombia]: Seeing Femicide/Feminicide as Immigration Injustice,” reveals how a combination of Colombia immigration policies and international failure to assist ColombiaFootnote ²⁹ have pushed many Venezuelan women into sex work. Venezuelan women are targeted because they are vulnerable, possessing fewer rights. Venezuelan immigrants are routinely subjected to degrading, sexist language, which actively disempowers them. Femicide is the most violent manifestation of systemic sexism and racism.

Feminism has a more oblique, but nonetheless important role in Marcia Morgan's Care Ethics and the Refugee Crisis, which builds on recent developments in feminist care ethics and political theory to overcome the challenges of justly caring for refugees and other forced migrants. Morgan highlights the ways in which care is both necessary and dangerous. Appropriate care for distant others is necessary to motivate political action and to contest hostile and oppressive policies. But at the same time, care can be inappropriate, invasive, or paternalistic. Moreover, nationalists, fundamentalists, and neo-fascists frequently mobilize care to depict immigrants and refugees as threats to their communities.

Morgan builds her project around the aesthetic, ethical (political), and religious thought of Søren Kierkegaard. For her, care begins with aesthetic experience, which can rupture our complacency and enable us to care for distant others. She analyzes Nilüfer Demir's controversial photograph of the drowned body of Syrian toddler Aylan Kurdi, which caused many people to at least momentarily care for the plight of Syrian refugees. Aesthetic experience alone does not tell us how to act ethically toward people. In some cases, it can reconfirm the limits of our imagination, distort reality, and reinforce our prejudices. To overcome its ambiguous nature, Morgan joins the aesthetic dimension with the ethical (political) dimension. Care ethics draws our attention to human relations and to our mutual dependency. Care can also be reconceived as the basis for contesting injustice, in which migrants and refugees model avant-garde political agency, promoting transnational justice through their actions (123–25).

Finally, Morgan considers religious-based care. Faith-based organizations are at the core of refugee and immigrant activism in most parts of the world, but political theorists have largely ignored their role. She finds resources in Kierkegaard's radical Christian exhortation to love one's neighbor, not because of shared identity, but because of need. Drawing aesthetic, ethical/political, and religious care together, Morgan ends with a reflection on the art-activist organization the Center for Political Beauty's event “The Dead Are Coming.”Footnote ³⁰ The Center exhumed the body of a Syrian woman in Sicily who drowned in the Mediterranean attempting to escape the Syrian war (her two-year-old daughter's body was lost at sea). The Center brought her for burial in front of the German Chancellery in Berlin, drawing attention to the actions and the consequences of inaction of the German people. Morgan describes the burial as “an act of contestation that strikes aesthetic, ethico-political, and religious registers” (169).

Race is another topic that has gained increased theoretical attention after being relatively neglected in liberal discussions of immigration.Footnote ³¹ Reed-Sandoval and Wolf center race and racism in their book, demonstrating how the discourse and law around “illegality” cannot be understood independently of the ongoing legacies of white supremacy in the United States.Footnote ³² Furthermore, racism cannot be understood independently of colonialization and imperialism, which are central themes in the collection Latin American Ethics, which Reed-Sandoval coedits with Luis Rubén Díaz Cepeda.

One of the most problematic tendencies in the political theory of migration is the stipulation that the author is only addressing Western, liberal, democratic societies. For example, Joseph Carens stresses that his audience is “ordinary men and women in North America and Europe who think of themselves as people who believe in democracy and individual rights and who want to understand the challenges posed by immigration into their societies.”Footnote ³³ This is problematic for a number of reasons. First, this perspective excessively narrows the field by ignoring south-south migration, which is more prevalent than south-north migration. Second, this approach is arguably a form of epistemic injustice, uncritically assuming the perspective of affluent, northern states. Third, this portrayal of North America (it is unclear if Mexico is included) and Europe (which privileges western Europe) as committed to democracy and individual rights frames commonplace policies such as externalization and immigrant detention as aberrations and poses an obstacle to grappling with the ongoing, central legacy of white supremacy.

Attention to Latin America is welcome and needed. To what extent does immigration ethics need to be contextual, taking into account specific histories or geographies? Are there universal principles? Do colonial or imperial histories create special obligations that should inform migration policy? Does place create morally salient connections across state borders (including for indigenous groups)?

Allison Wolf takes up some of these questions in Just Immigration in the Americas and her contribution to Reed-Sandoval and Díaz Cepeda's collection. In Just Immigration in the Americas, she places US imperialism at the center of her account of global oppression.Footnote ³⁴ Wolf mobilizes Marilyn Frye's and Marion Young's work to analyze migration through an account of global oppression.Footnote ³⁵ Wolf connects Young's five faces of oppression—exploitation, marginalization, powerlessness, cultural imperialism, and violence—to epistemic injustice, drawing on Ann Cahill to add a sixth face of oppression: derivatization. Derivatization occurs when people project their own desires or fears onto others, reducing them to extensions of their own identities (52).Footnote ³⁶ We see this in media depictions of migrants as invaders, exploiters, or even as voiceless victims. Derivatization is also a form of epistemic violence, in which migrants’ testimony is ignored, dismissed, or silenced.

As Wolf emphasizes, immigration in the Americas cannot be understood independently of the history of US intervention in the region, including explicit exportation of its immigration policy. The United States outsources migration enforcement to Mexico, so the US border effectively begins in Guatemala, when not further south. We have seen this in recent years with the so-called Migrant Protection Protocols, under which people claiming asylum were returned to Mexico for processing, often under conditions where they were kidnapped, extorted, raped, or killed.Footnote ³⁷

The essays in Amy Reed-Sandoval and Luis Rubén Díaz Cepeda's Latin American Immigration Ethics suggest many ways in which the literature can continue to move forward, both methodologically and in terms of subject matter. Latin America merits much more attention from political theorists. The comparatively liberal immigration policies in most South American countries serve as a helpful contrast.Footnote ³⁸ At the same time, many countries in South America struggle with large numbers of migrants, many fleeing Venezuela, placing strains on already limited infrastructure (Wolf 2020). This raises a serious challenge for political theorists: Can normative prescriptions for the Global North generalize to different parts of the world?

One of the pleasures of Latin American Immigration Ethics is its eclecticism, which sits well with the editors’ capacious definition of Latin American philosophy: “as including both philosophy produced by Latin Americans and their descendants and/or philosophy that features substantive engagement with issues of concern to the Latin American and Latinx communities” (9). Carlos Pereda draws on the corridos of legendary norteño band Los Tigres del Norte, which he calls “a purgative against despair” (220–40). Lori Gallegos raises the topic of linguistic oppression, particularly in the still too common practice of children serving as interpreters for their parents, forcing them at an early age to learn to navigate medical and legal services (243–64).

A more central theme is colonialism, imperialism, and the need to engage with Southern perspectives in our political theory. José Jorge Mendoza calls for the decolonization of immigration justice by decentering Anglo-American and European perspectives, including in the political theory of migration literature (44–70).Footnote ³⁹ Mendoza advocates for more attention to how Latinx scholars such as Natalie CisnerosFootnote ⁴⁰ have relied on Gloria Anzaldúa's Borderlands Footnote ⁴¹ to enrich our understanding of subjectivity and biopower or how José-Antonio OroscoFootnote ⁴² has drawn inspiration from Cesar Chavez's social and political thought for social protest.

Another resource that Mendoza mentions and Luis Rubén Díaz Cepeda (173–97) and Amos Nascimento and Margaret Griesse deploy in their essays (91–124) is liberation theology and philosophy. Liberation theology has been central to many Latin American political movements, with its combination of a Catholic gospel dedicated to the alleviation of poverty and oppression and an engagement with radical political economy.Footnote ⁴³ Its secular counterpart, liberation philosophy develops out of this tradition, in close dialogue with European philosophy, but centering the perspective of the oppressed and calling for solidarity through collective political organization.Footnote ⁴⁴

Attention to Latin American immigration ethics should awaken us to how much work there is to do. There is very little work in the political theory of migration that centers Africa and Asia (and when they are discussed, it is often from a European, North American, or Australasian perspective). Silvana Rabinovich begins to develop connections by focusing on the border walls confronted by Mexicans, Palestinians, and Saharawis in Western Sahara (198–219), but there is much more work needed, both by in-depth normative investigation of particular places and by drawing connections. We are only beginning to move toward a truly global political theory of migration.

As the books in this review essay demonstrate, it is an exciting, if perhaps unsettling time to be working in the political theory of migration. Migration has moved from the fringe to the center of the discipline, calling into question our methodological and epistemic assumptions. The incorporation of fieldwork and perspectives from the Global South promises to continue to challenge and expand the field. Theorists will benefit from closely engaging all of the works discussed here. It will be fascinating to find out how they build on them.