This is an excellent book. Not only does Kok-Chor Tan provide a strong argument for cosmopolitan justice in the face of various defenders of nationalism and patriotism who see their claims at odds with cosmopolitanism, but in doing so he offers a cogent overview of the relevant literature and provides order to discussions surrounding cosmopolitanism where there has been a great deal of confusion.

Tan's overall purpose is to argue for a specific form of cosmopolitanism, that is, cosmopolitan justice, which he sees as compatible with nationalist and patriotic commitments, though not unreservedly so. In order to do this, he follows three major lines of argument. First, he develops a version of Rawlsian-inspired cosmopolitanism that, he argues, provides a solid basis for global justice. Second, he explores the arguments in defense of nationalism and shows how liberal nationalism rightly understood should be considered compatible with his version of cosmopolitanism. In a final section of the text, he shows how one can be a committed cosmopolitan on his terms and still acknowledge the independent value of patriotic commitments.

So what is the form of cosmopolitanism defended by Tan that seems on the surface to do the impossible? As he exposes through an extremely helpful overview of the forms of cosmopolitanism, his goal is to propose a “strong” (i.e., not just positing a minimal material threshold as a measurement of equality and a policy of humanitarian assistance, but a global redistributive framework that provides a new set of rules to correct structural inequalities) but “moderate” (i.e., recognizing the value of commitments independent of cosmopolitan morality) moral cosmopolitanism about justice (p. 12). In its most basic form, cosmopolitanism is defined by Tan as a framework committed to defending the individual as the ultimate unit of moral worth (p. 35), and he rejects the notion that this necessitates any defense of a world state. Indeed, he is emphatic that a commitment to the basic rights and liberties of individuals and the expression of basic concern for individuals requires first and foremost a reassessment of the global economic order where evidence of injustice and inequality are most clearly evident. How the resolution of these priorities of economic justice plays out in political and institutional terms is clearly of secondary importance to the author.

Tan places himself in a line of attempts (e.g., Charles Beitz and Thomas Pogge) to harness the principles of Rawlsian justice to the global arena in ways that Rawls was reticent to do. What is particularly significant and novel about Tan's argument is that he provides this defense of cosmopolitan justice at the same time as he takes into account the objections to cosmopolitanism raised by defenders of nationalism and patriotism. He is able not only to circumvent these objections but indeed to argue that those committed to liberal nationalism must consider themselves to be defenders of his version of cosmopolitanism. He does so thoughtfully by considering the scope of the different claims. As a defense of a global basic structure relevant to matters of distributive justice, not only is his idea of cosmopolitanism rightfully recognized to be compatible with the liberal nationalist project of cultivating community for the purpose of promoting social justice; but by its goal of mitigating forces of economic oppression and injustice at the global level, his cosmopolitanism is also considered a precondition for a commitment to the principles and universal practice of cultural autonomy and self-determination that are central to liberal nationalism.

But what about a thicker view of local attachments in the form of patriotism? Tan seeks to do justice to the strength of those arguments that acknowledge the independent moral force of patriotic attachments by rejecting those who defend these attachments solely as means to cosmopolitan ends. He argues that the defenders of cosmopolitanism have been misguided in their focus on assessing the moral grounds for patriotic commitments, and instead he suggests that what should really be of concern to committed cosmopolitans is the practical upshot of those commitments. In other words, cosmopolitanism flowing from a moral commitment to an impartial idea of justice should be seen as informing an economic framework and basic rules of interaction that provide a set of limits on what patriotic commitments, however justified, can demand or require. By carefully considering and differentiating spheres of cultural identity and more basic moral obligation, Tan is able to provide a cogent defense of cosmopolitanism that does not have to unduly jettison some of the literature's more convincing claims about our need for cultural attachments and community, despite our commitments to universal principles. Still, as he recognizes, the principles of justice will always set boundaries or limits on what these local attachments can legitimately demand of us: “The task for cosmopolitans is not to show that patriotic commitments per se are rationally indefensible, but to show that defensible forms of patriotism do not violate the demands of cosmopolitan justice…. The crucial question for global justice is how the rules of the global structure are to be determined” (p. 197).

While this overview shows the broad contours of Tan's argument, it is important to note that in a masterful coverage of the existing literature, the author is able to lay out and defend his position in the face of multiple variants of the positions with which he engages. Furthermore, he is able to represent this complexity with admirable clarity, which makes the book an extremely useful one for anyone with an interest in cosmopolitanism and global justice.

Still, precisely because of his sympathy (though within limits) for a more “thick” understanding of patriotism, it is surprising that Tan does not acknowledge in this work what could be seen as a central objection to the idea of the primacy of an impartial idea of justice. Indeed, in his attempt to address Rawls's objections to the idea of a global basic structure for basic reasons of liberal tolerance, Tan suggests that while liberal principles of civil and political rights may be objectionable to nonliberal societies, there is no reason to believe that these same societies will reject liberal principles relating to economic and social rights (p. 77). Furthermore, if nonliberal societies can regard themselves as benefiting in material terms in a global system of distributive justice, then there is no reason, according to Tan, for them not to espouse the principles of distributive justice that he advocates at the global level (p. 78). While clearly in practice he does not expect a global consensus on his principles for his understanding of justice to be operative (and he clearly goes to great pains to distinguish between what he calls “conventional” moral convictions that reflect existing points of view and “commonsense” morality that stands up to the rigor of critical reason and a sense of the prior force of independent moral requirements), there is clearly something problematic with an idea of justice that sidesteps the moral positions articulated by those who are regarded as the clearest victims of injustice. It is not obvious that those who have been oppressed by a global system of economic inequality will be trusting or will acquiesce in a project of economic justice that derives from the same traditions that had oppressed them. Is it not incumbent on any solid project of cosmopolitan justice not to justify its integrity through an appeal to abstract impartiality, but rather to show on the ground and in the trenches that it is a philosophical commitment that is compatible with a diversity of global traditions previously marginalized in philosophical discourse? Without such work, such a project risks falling largely on suspicious if not deaf ears.

Still, for most of those who feel that the project of cosmopolitanism can be sufficiently defended within the boundaries of the Western philosophical tradition, Justice Without Borders offers much food for thought and is extremely helpful in clarifying and ordering a vast array of relevant literature on the topic. It should be a recommended text in any upper-division and graduate course devoted to the study of cosmopolitanism.