Andrew Bacevich, an expert on U.S. foreign policy and military affairs, talks about the forces that have shaped U.S. national security and the rise of a "perpetual war" that affects the economy, society and politics of the United States, and our place in the world. What is the proper role of the U.S. military in the world? Can terrorism be defeated militarily? Can the aspiration of unchallenged global dominance be sustained? A retired army colonel and professor at Boston University, Bacevich addresses these issues with a sense of realism and a historical perspective that challenges many common assumptions.