North Americans are fond of saying, almost reverentially, that the United States is an immigrant nation. And indeed it is. But therein is a long and complicated tale, fraught with ambiguity, heated debates and major shifts. In a new book Aristide Zolberg analyzes this story with incomparable erudition and fresh insight.

Typically, immigration policy has been treated as a secondary subject in U.S. history, except when episodic bursts of nativism and anti-immigration sentiment become dominant. Zolberg, who is one of the world’s outstanding scholars in the field of human migration studies, convincingly corrects this outlook. As Zolberg thoroughly documents, immigration policy has been a matter of constant concern throughout U.S. history.

Unlike people in European countries, Americans were able to design the nation they wanted. That is, they could make decisions about whom to recruit and whom to keep out or eliminate. For example, prior to independence colonial leaders were eager to recruit new settlers, and they made it relatively easy for them to become assimilated. A little-recognized fact is that this desire was in conflict with the policies of the British crown—a conflict that became so intense that settlement policy was among the grievances enumerated in the Declaration of Independence.

Colonial policy, Zolberg comments, was unusually inclusive. Though the voluntary immigrants were almost all European, there were no restrictions on the basis of religion or national origin. At the same time, however, colonists were “brutally exclusive” with regard to African Americans and American Indians.

This book is certain to become the standard work on the history of U.S. immigration policy. It is not a quick read, so it will appeal to scholars more than to a general audience, but there may be many readers who would benefit from consulting Zolberg’s discussions of particular periods in U.S. history. The sections dealing with post–World War II developments are especially pertinent for persons involved in contemporary debates about immigration. The final chapter is an important discussion of why it is ethically imperative for the U.S. to continue to welcome immigrants.

Zolberg brings exceptional clarity to the ways that economic and political interests are operative in the determination of immigration policy. Two primary considerations are often in conflict. First, there are economic interests. In business circles immigrants are viewed as human capital. Access to low-wage workers in a context of free markets is highly desirable. Therefore, persons who are conservative on the political spectrum tend to want a more liberal immigration policy.

At the same time, labor has been historically more resistant to immigration, viewing immigrants as competition for valued jobs and higher wages. Whereas labor is typically more liberal on many economic and political issues, it has historically been more restrictive on immigration. Interestingly, this has been changing recently as labor unions see low-wage immigrant workers as prime candidates for union recruitment. It is fascinating to see corporate interests and labor interests sometimes aligned, however uneasily, on immigration policy.

A relatively recent economic question is whether immigrants, especially undocumented ones, are a burden on taxpayers. Although economic estimates and immigration advocates are likely to point to the substantial benefits that immigrants bring, many people have become increasingly alarmed by the presumed costs of social services for this population. Prior to the New Deal, the notion of rights or entitlements for immigrants was not an issue, although keeping “paupers” out of immigrant flows has been a longtime policy objective.

The other important issue in immigration policy is cultural identity. What degree of cohesiveness does a political culture require, and what are the primary elements of cultural unity? “How different can we be and how alike must we be?” Zolberg asks. In U.S. history, contests about identity have involved race, religion and language. At an early stage Thomas Jefferson argued for the importance of homogeneity for republican states, and prior to the immigration legislation of 1965, Zolberg shows, the U.S. was a European immigrant nation. It had pushed away or exterminated American Indians, and it had enslaved African Americans, tried to remove them to Africa and then excluded them. After a brief period of Chinese and Japanese immigration, it had rigorously restricted immigration from Asia. Since 1965, however, U.S. policy has been far more cosmopolitan. The U.S. is, in Zolberg’s words, “the first nation to mirror humanity.”

Although religion is less influential as an identity issue now except in the case of pockets of anti-Muslim feeling, language and race are major elements in current restrictionist sentiment. Restrictionists make a variety of arguments based on the cultural otherness of Mexicans especially. Many expressions of hostility toward Mexicans are coded because racist discourse is not acceptable in the public arena, but their otherness is depicted as threatening to the cultural unity of the American nation.

For Zolberg, the persistence of economic interests and cultural identity as major elements in the determination of immigration policy helps to explain the emergence of strange political bedfellows. In the current situation, senators Edward Kennedy (D., Mass.), John McCain (R., Ariz.) and Sam Brownback (R., Kan.) joined to support a comprehensive immigration bill. On the other side of the issue, in the state of Colorado conservative Republican Tom Tancredo and maverick Democrat Dick Lamm joined in advocating highly restrictive legislation.

As Zolberg’s analysis illumines, some Republicans are more concerned about the economic value of access to low-wage immigrant labor while others are more concerned about perceived threats to U.S. cultural unity. Among Democrats, who may be critical of business interests, there is a conflict between those who embrace multiculturalism and those who believe that cultural unity is being threatened. Some Democrats, for example, believe that the U.S. will never be able to establish strong economic-justice policies, such as universal health care, as long as the public believes that immigrants will be major beneficiaries. An additional element is the growing political influence of Latino constituencies who regard immigration as an economic and cultural benefit.

In his detailed analysis of the interplay of interests shaping immigration policy, Zolberg gives attention to debates about varied policy proposals, not just to the legislation that was finally adopted. He writes as a political realist who regards political, economic and cultural interests as determinative. It is therefore a welcome surprise when he takes on the voice of a political philosopher in his final chapter, in which he discusses what he believes U.S. immigration policy should be. His ethical vantage point is that of the “cosmopolitan strain of liberal egalitarianism, tempered by a dose of realism”—that is, the perspective that each human being is of equal value and that the primary unit of humanity is not the nation but the species.

Since we share a common humanity, Zolberg contends, it is wrong for the privileged nations to close their borders to fellow human beings who exercise their moral freedom to move rather than acquiescing to their condition of inequality. Moreover, in the context of globalization the only feasible way for nations to adopt highly restrictive immigration policies is to establish police-state measures.

Zolberg argues that we should loosen the rigidities of nation-state territorial sovereignty by changing the basic question from “Whom should be admitted?” to “What gives a group the right to exclude others?” The burden of justification should be on exclusion rather than admission. Zolberg does not favor open borders. As a concession to realism, he writes that the consequences of unlimited immigration would be harmful to both citizens and immigrants, but he maintains that the legitimacy of U.S. restrictions on immigration are dependent on the nation’s commitment to reducing international inequalities. And whatever measures the U.S. may justifiably use to limit immigration, he says, we need to learn to live with the imperfections that will result in some continuing unauthorized immigration.

The cosmopolitan ethical perspective is of crucial importance for many of the world’s most pressing issues. Zolberg’s reflections are profoundly challenging and pertinent. My primary critique is that he fails to link his ethical reflections in the final chapter to the historical analysis in the bulk of the book. This is all the more disappointing because he has the wisdom to do so. Without addressing normative questions in their historical context, ethical reflection seems quite unrelated to the powerful interests that actually influence U.S. policy. Regrettably, Zolberg perpetuates the all too common notion that there is a deep divide between ethics and public policy rather than addressing how his ethical views can be historically influential. It is not apparent how his powerful cosmopolitan perspective can gain any political traction in the arena of immigration debate. Who will be the political bearers of such a perspective?