" "We need a nation," declared a certain Phillippe Grouvelle in the revolutionary year of 1789, "and the Nation will be born."--from Nationalism Nationalism, often the scourge, always the basis of modern world politics, is spreading. In a way, all nations are willed into being. But a simple declaration, such as Grouvelle's, is not enough. As historian Liah Greenfeld shows in her new book, a sense of nation--nationalism--is the product...