Few, if any phenomena affecting Western Europe as a whole since 1945 have been more far-reaching in their immediate effects to politics and society over the long term than the experience of immigration. This work analyses why the major immigrant-receiving states of Western Europe historically permitted and often abetted relatively high levels of postwar migration, and assesses how contemporary governments attempt to govern immigration flows and manage the domestic social and political fallout which it inevitably yields. The volume addresses these questions within the context of the decision-making logics that have demonstratively governed postwar migration to Western Europe in each of its three distinct, but interrelated, waves or phases - labour migration, family migration, and humanitarian or forced migration. The text shows that postwar migration to Western Europe, in all of its phases, has been governed by a set of mutually reinforcing and mostly compatible logics.