To intervene or not to intervene: that is the question this country has continually faced since becoming a major player on the international stage. No one has written with more perception and passion about this moral and strategic dilemma than ROBERT KAGAN, an advocate for America’s active presence in the world. His new book is the deeply researched story of American foreign policy in the first four decades of the 20th century. He will talk about the book, about those foundational years, and the early and ongoing tensions between isolationism and engagement.