Today there are twenty million refugees who have crossed international borders to escape violence and abject poverty. Forty million more have been displaced within their own countries. In 2015, half a million refugees have poured into Europe, with thousands dying at sea or in cramped smugglers’ vans. In America, tens of thousands of children have been detained while crossing the border, and the bodies of hundreds more have been recovered from the desert. These facts cry out for a response. Within the European Union, countries debate who will receive the migrants, and in what numbers. In America, we debate what to do about undocumented aliens, how many visas to allocate to highly skilled workers, and whether a long-term policy of favoring family reunification should remain in ­effect.

The norms of international law stipulate that people have a right to emigrate from their homeland but not a right to immigrate to any particular country. Right of entry can be granted only by the country of destination. Scholars of international relations have developed two approaches to guide these considerations: communitarianism and cosmopolitanism. The policies we favor follow from our loyalty to one of these two approaches. The communitarian favors a more restrictive approach; the cosmopolitan a more open one.

Both seek to promote human dignity. The communitarian sees strong nation-states as crucial. In The Law of Peoples, philosopher John Rawls argues that international peace and justice can only be advanced through well-governed societies. The foundation of a humane global order is the stability provided by nations that take care of their own people and respect the sovereignty of other nations. There are bound to be injustices in this system. Some countries will accord more respect for human rights than others. But without well-governed sovereign nations—strong national communities—the global system will decay into far worse disorder, and the rule of law will weaken within countries.

Recent history supports this view. To the extent that the post–World War II international community has become more humane and prosperous, the cause has been strong, constitutional states. Political ethicist Michael Ignatieff argues: “If we want human rights to be anchored in the world, we cannot want their enforcement to depend on international institutions and NGOs. We want them anchored in the actual practice of sovereign states.” Only national communities have the power consistently to protect rights and enforce laws. Therefore, to advance human dignity and prosperity in the world, we must nourish strong nation-states that are solicitous of the well-being of their citizens and respectful of the sovereignty of other states.

We have a moral duty to care for refugees, but the communitarian insight identifies a concurrent obligation to maintain our own ­societies as stable and well-governed. That means political communities must regulate their borders. Drawing on Rawls, political theorist Stephen Macedo argues, “An immigration policy cannot be considered morally acceptable in justice unless its distributive impact is defensible from the standpoint of disadvantaged Americans.” This does not mean we should not assist foreigners or promote generous immigration policies. Rather, it requires that we give priority to the needs of the most vulnerable in our political community, which today means unskilled American workers. They are the most likely to suffer economically as a result of a larger influx of low-wage immigrants.

For the communitarian, solidarity is paramount. Immigration will always have a disparate economic impact on a country’s citizens. Someone who owns a factory often benefits from immigration because it increases the supply of labor, driving down wages. Technology firms also benefit by becoming able to draw upon a global talent pool rather than a more limited national one. Although Macedo does not mention it, there are disparate cultural impacts as well. College-educated professionals often work for international corporations and move as job opportunities arise. This class of people rarely feels ­disoriented by rapid changes in the demographic makeup of society because they see the system working for them. Working-class Americans have fewer resources for navigating cultural change and stand to lose more from it. Whether for economic or cultural reasons, the communitarian returns to Rawls’s insight: The precondition for justice is a well-governed society, and this requires civic trust and cooperation, which is to say solidarity. To achieve and maintain that trust, the rich and powerful need to give priority to the needs of the poor and vulnerable.

The economist Paul Collier, author of The Bottom Billion, also argues that meeting human needs requires sustaining solidarity—what he terms “mutual regard.” In societies without this regard, the rich do all they can to evade taxes, and they often use their power to protect their assets, even at the expense of solidarity. The end result is class conflict and civic strife. When a society is unified, those with greater resources are willing to assume greater burdens to advance society as a whole. Trust and cooperation do not arise automatically, however. They must be created and sustained. Bad policies that systematically disadvantage one or another sector of society can impair solidarity, as can dramatic social changes. Collier argues that mass immigration can easily undermine solidarity by impeding “mutual regard.” In his words, “moderate migration is liable to confer overall social benefits, whereas sustained rapid migration would risk substantial costs.” He cites a study by Robert Putnam showing that higher levels of immigrants in a community are associated with lower levels of social trust. The reduced solidarity was not limited to lower levels of mutual trust between immigrants and natives, but also undermined trust among migrants themselves—a striking outcome that indicates how the dislocations associated with migration can have a destabilizing effect on everyone.

The cosmopolitan approaches international issues from a fundamentally different perspective. He views the world as a coherent global society united by the simple fact of our common humanity, and often regards the nation-state as an impediment to international justice. For him, war, famine, and human rights abuses are a consequence of the global order based on sovereign states that Rawls affirms because such a system facilitates and fosters competition and conflict among states.

One scholar who champions this perspective is ethicist Peter Singer. In One World, Singer argues that the rise of the “global village” demands a “new ethic” that can serve the interests of all persons ­without regard to particular affiliations. Where Rawls pursues justice through states, Singer promotes a global system in which national sovereignty is no longer important. “A global ethic should not stop at, or give great significance to, national ­boundaries. National sovereignty has no intrinsic moral weight.”

In its purest form, the cosmopolitan approach rightly insists that, from a moral perspective, people are more important than states. The communitarian ultimately agrees. They differ, however, in their judgment about the role of the nation-state. The cosmopolitan envisions the direct application of moral principles on a global scale, and regards the nation-state as an impediment to human rights and global justice. Cosmopolitans thus call for a more integrated and open global society that advances human rights on a uniform basis. By stressing transnational bonds, the cosmopolitan perspective affirms the equality of persons and universality of human dignity. According to Martha Nussbaum, we should shift our allegiance from the nation to the international scene, thereby nurturing a global “moral community made up by the humanity of all human beings.”

In light of these commitments, the cosmopolitan views limitations on immigration with suspicion. The priority Macedo accords to a country’s own citizens is deemed indefensible ethnocentrism. A cosmopolitan such as Peter Singer has no interest in disputing Collier’s analysis of the negative impact of immigration on particular populations already resident in a country. Instead, he rejects the notion that the fact of my having been born in the United States should give me greater standing than a migrant from Eritrea. A cosmopolitan might allow that immigration restrictions remain a practical necessity for now, but he thinks our long-term aim should be to ­eliminate borders and allow for the free migration of all people. For the cosmopolitan, the only community with moral standing is the human community as a whole.

The Christian faith assumes the inherent dignity and equality of all persons. A belief in what St. Paul speaks of as the law written on the Gentiles’ hearts leads us to view the world as a coherent moral community. At first glance, therefore, cosmopolitanism seems a fitting expression of Christianity’s outlook. This has been especially true for the Catholic Church. The Protestant Reformation unleashed a century of conflict that culminated in the Thirty Years’ War (1618–1648). The war, which claimed more than 20 percent of the German population, ended in 1648 with a series of treaties collectively known as the Peace of Westphalia. This accord inaugurated the modern nation-state by giving political leaders supreme authority, including the right to decide the state’s official religion, within their territorial boundaries. It was in this period that the nation-state emerged as an integral cultural and spiritual entity, providing the basis for modern European, and eventually international, politics.

Though Westphalia brought respite from religious wars, the Catholic Church adamantly opposed the accord and its recognition of the spiritual sovereignty of modern nations. In 1650, Pope Innocent X issued a bull condemning it as “null, void, invalid, iniquitous, unjust, damnable, reprobate, inane, empty of meaning and effect for all time.” For the Roman Church, the rise of state sovereignty was not simply an affront to the Church’s temporal influence. It also challenged Western Christianity’s historic conception of a unitary global order, one that went back to Constantine and the fusion of religious and imperial authority in the fourth century. As a result, throughout the seventeenth, eighteenth, and nineteenth centuries, the Catholic Church continued to judge the Westphalian primacy of state sovereignty contrary to the natural order established by God. As late as the nineteenth century, the Church still banned the writings of Hugo Grotius, an early defender of the sovereign state and the father of modern international law.

The Catholic Church continues to emphasize the solidarity and universality of the human family. Pope Paul VI spoke against undue emphasis on the nation-state, casting it as “opposed to the formation of a world which is more just and which is better organized toward a universal solidarity.” Benedict XVI called for the development of “a true world political authority.” This cosmopolitan emphasis leads to solicitude for immigrants. In his encyclical Pacem in Terris (1963), Pope John XXIII stipulates, “Every human being has the right to the freedom of movement and of residence within the confines of his own State. When there are just reasons in favor of it, he must be permitted to emigrate to other countries and take up residence there.”

In an address in 1985, Pope John Paul II declared, “Every human being has the right to freedom of movement and of residence within the confines of his own country. When there are just reasons in favor of it, he must be permitted to migrate to other countries and to take up residence there. The fact that he is a citizen of a particular state does not deprive him of membership to the human family, nor of citizenship in the universal society, the common world-wide fellowship of men.” And in his recent address to Congress, Pope Francis emphasized the need to respond compassionately to those who migrate to improve their standard of living. “On this continent, too, thousands of persons are led to travel north in search of a better life for themselves and for their loved ones, in search of greater opportunities. Is this not what we want for our own children?”

Christian skepticism toward communitarianism is not limited to the Catholic Church. In Re-­Creating America, a book on immigration ethics, Dana ­Wilbanks, a Protestant ethicist, rejects the Westphalian system of nation-states, arguing that territorial borders protect “unjust privilege.” In his view, “the presumption in Christian ethics would seem to be an open-border policy.” M. Daniel Carroll R., an Evangelical Bible professor, argues in Christians at the Border that Scripture provides a framework for assessing immigration. As Carroll sees it, the biblical disposition is more concerned with inclusion than exclusion, with hospitality than with law. Immigration “is a topic close to the heart of God and inseparable from the life and mission of God’s people. Openness to sojourners is a virtue, and concern for their well-being is manifested tangibly in Old Testament law.”

There can be no doubt that Christianity’s moral and evangelical universalism accords with many aspects of the cosmopolitan perspective. We need to keep this dimension in mind when we engage, as Christians, in debates about immigration. But cosmopolitan ideals do not provide a sufficient basis for creating immigration policy. It needs to be balanced with communitarian insights.

The most important dimension of the communitarian approach is its emphasis on the bonds that people have to their nations. God knows each of us in the uniqueness of our lives, but he calls us to community. We are social animals. The Old Testament tells of his people, Israel, and the New Testament of the possibility that we all might enter into God’s chosen people, the Church, by way of baptism and faith in Christ. At Pentecost, the universal message of salvation is not declared in Esperanto, but in the languages of the peoples gathered in Jerusalem. Christian revelation encourages us to recognize that our humanity is expressed through communal life. Having an inheritance—a native language, a native culture, a particular place in the world—is especially important to human well-being. To be sure, modern nation-states are often arbitrary political creations. Belgium includes different ethnic groups divided by language. Nigeria contains different tribal groups and religions. Nevertheless, the nation-state can foster social and political bonds that enhance human dignity by fostering solidarity. Nazism, fascism, and the horrors of World War II have made Europeans very critical of nationalism. But a hyper-critical attitude can blind us to the positive goods that can be realized when a strong sense of national unity motivates people to make sacrifices for the common good.

Communitarianism also encourages an acceptance of, and even support for, political pluralism. Given our fallen condition, this leads to a realism that is too often absent from cosmopolitans. The Westphalian global order is based on state sovereignty. It can lead to competition and conflict among member states, but it also creates the conditions for cooperation in promoting the common good and confronting evil and injustice. The United Nations itself presupposes (and is formally committed to protecting) the sovereign integrity of its members. Its relatively ineffective influence on geopolitics dismays many cosmopolitans. But the upshot has not been disorder or perpetual global conflict. A global system based on national sovereignty allows states to challenge each other and achieve balances of power through coalitions. We do well to remember that the evils of imperialism stem from the fact that European nations refused to respect the sovereignty of non-European peoples. Nazism was an imperial project that refused to recognize the sovereignty of non-Germanic peoples, even in Europe.

Another strength of communitarianism is its acknowledgment of the important role of the state in advancing human rights. It recognizes that strong government institutions are essential for making and enforcing laws to protect human dignity. As St. Paul makes clear in Romans 13, the coercive power of the state has a crucial role to play to ensure that justice is done. Sustaining the nation-state is thus especially important for Christians. Of all people, Christians should be aware of how greed and selfishness can undermine the common good. For this reason, we always need to guard against any weakening of legitimate governments. Such a weakening undermines states’ capacity to sustain the rule of law.

A Christian approach to migration should be rooted in both the universal ambitions of cosmopolitanism and the concern for solidarity we find in communitarianism. How best to combine them will vary from one time and place to another. Some circumstances require us to shore up national solidarity. In other situations, we need to extend a welcome to immigrants. Today, the United States faces the challenge of enforcing immigration laws. Illegal immigration undermines the rule of law and creates a widespread worry that nobody is in charge. We are also debating how to respond to the undocumented immigrants who are currently living in the United States. The communitarian model provides a helpful framework. Too often, commentators describe populist anger about immigration as a sign of racism or nativism. A communitarian analysis offers more subtle and accurate insight into popular discontent. Debates about a “pathway to citizenship” can be enriched if we ask how proposed policies do or do not promote national solidarity.

European countries face a different challenge at present. Unlike the United States, where very few immigrants are refugees, the sovereign nations of Europe are presented with the immediate needs of people fleeing persecution and conflict. They are victims of failed states—a reminder of the importance of well-governed societies for any global system of justice. This refugee crisis calls for a cosmopolitan perspective, one that asks us to give priority to those fleeing violence over the communitarian needs of individual states. What this means for actual national policies is difficult to determine. Many of the migrants are not coming directly from failed states like Syria but through other states—like Turkey—that are stable. By travelling as far as they can west and north, they are seeking not immediate respite from violence so much as greater economic opportunity. These are worthy aspirations, but ones that must be weighed by communitarian as well as cosmopolitan criteria.

The cosmopolitan outlook dominates declarations and documents on U.S. immigration policy issued by Catholics, mainline Protestants, and Evangelicals. Many acknowledge government responsibility to regulate borders, but the fundamental message is that all people are made in God’s image and that they are a part of a moral community that includes us all. As a result, religious advocacy groups invariably favor comprehensive immigration reform that will allow for increased legal immigration, more rapid family reunification, and the legalization of irregular aliens.

While admirable in its spirit of generosity, this approach over­emphasizes social inclusion—“welcoming the stranger.” It does not give adequate attention to communitarian concerns, such as obedience to lawful authority. Nor does it consider the effects of immigration on the most vulnerable members of society. A cosmopolitan tendency to disregard the perennial need to support the state and renew social solidarity is a major shortcoming of many church-sponsored analyses of U.S. immigration. Terms like nation, state, government, rule of law, citizenship, passport, and legal justice are minimized or even absent, while the moral language of inclusion, hospitality to strangers, and compassion dominates. “Strangers No Longer,” the joint pastoral letter by U.S. and Mexican Catholic bishops, celebrates the rights of persons and the universal solidarity of the international community but fails to acknowledge the role of the nation-state in protecting human rights and advancing economic prosperity. The bishops write:

We recognize the phenomenon of migration as an authentic sign of the times. . . . To such a sign we must respond in common and creative ways so that we may strengthen the faith, hope, and charity of migrants and all the People of God. Such a sign is a call to transform national and international social, economic, and political structures so that they may provide the conditions required for the development for all, without exclusion and discrimination against any person in any ­circumstance.

The bishops seem to see American society and its institutions as a market rather than a community united by a common culture—a place where ­strangers work and pursue their economic interests, not a society where people share common bonds and shared responsibilities.

The National Association of Evangelicals ­adopted a two-page declaration on immigration in 2009. Although the declaration acknowledges the reality of nation-states, it suffers from the same one-sided cosmopolitanism. It minimizes the role of civil authorities in regulating migration. The short statement highlights biblical principles, describes current problems, and offers policy recommendations. But rather than illuminating the tension involved in loving aliens and recognizing our collective responsibility to each other as citizens, the resolution proceeds to call for a more flexible, expansive immigration policy.

The communitarian view reminds us that human beings achieve their full humanity through social interaction in specific communities. We are ennobled by our sense of belonging within families, neighborhoods, and nations. The political theorist Benjamin Barber has observed that the challenge we face in our time is not to eliminate patriotism and nationalism. A cosmopolitan sense of belonging to a universal community is unlikely to satisfy our need to experience solidarity. Our goal, says Barber of patriotism and nationalism, is “to render them safe.” “Cosmopolitanism as an attitude may help us in that effort,” he writes, “but cosmopolitanism as a political destination is more likely to rob us of our concreteness and our immediacy and ultimately can only benefit the less wholesome aspects of the yearning for community and identity.”

There is no guarantee that a post-national future with open borders will usher in the cosmopolitan utopia. It may well encourage more primitive and violent forms of solidarity of the sort we see in ISIS and ­other Islamist movements. Or it may lead to a soulless, ­me-centered consumerism governed by multi-national financial interests that have no concern to promote the common good or encourage solidarity. Therefore, when we set about to think morally about immigration, we do well to keep in mind Gertrude Himmelfarb’s observation about our essential human needs. Our policies need to be open, inclusive, and generous, yes, but they also need to respect and promote the “givens of life,” family, religion, heritage, history, culture, tradition, and nationality.

Mark R. Amstutz is professor of political science at Wheaton College.