Every scholar likes to think that what he or she studies is of capital importance. For that reason alone, this ambitious book would have to please immigration specialists. “Demography is destiny” is Rey Koslowski's thesis, boiled down, and in his view it is almost impossible to overrate migration's impact on international politics. While guilty of overreaching in a few spots and failing to appreciate the role of politics in quite a few more, he makes a compelling case overall. His bold work both brings a stimulating perspective to a multidisciplinary area of study that is still seeking its center of gravity and serves to remind the field of international relations (IR) that migration deserves its full attention.