Guests and Aliens presents a comprehensive analysis of worldwide immigration by one of the world's leading experts on globalization. Putting the current crisis' of immigration into a historical context for the first time, Sassen suggests that the American experience represents only one phase in a history of global border crossing. Sassen explores the causes of immigration that have resulted in nations' welcoming incomers as 'guests' or disparaging them as 'aliens,' and outlines an enlightened approach to improving US and European immigration policies.'