Saskia Sassen, one of the world’s leading experts on globalization, presents a comprehensive analysis of worldwide immigration. Establishing the current “crisis” of immigration in a historical context, Sassen puts today’s situation into perspective as one phase of a global history of border-crossing. She describes the mass immigrations of Italians and Eastern European Jews during the 19th and 20th centuries, and the international dislocations – particularly after the end of World War II – that have endangered the “refugee” concept. Using these examples, Sassen explores the causes of immigration that have resulted in nations; either welcoming new arrivals as “guests” or disparaging them as “aliens”. She then outlines an “enlightened approach” (Publishers Weekly), to improving our own immigration policies.