Since the end of the Cold War, and especially since September 11, few issues have been more hotly debated than the United States' role in the world. In this hard-nosed but sophisticated examination, Colin S. Gray argues that America is the indispensable guardian of world order. Gray's constructive critique of recent trends in national security is holistic, rooting defense issues and prospective answers both in U.S. national security policy, broadly defined, and in the emerging international security environment. Colin S. Gray is professor of international politics and strategic studies at the University of Reading, England, and senior fellow at the National Institute for Public Policy in Fairfax, Virginia. He is the author of seventeen books, including Modern Strategy and Strategy for Chaos: Revolutions in Military Affairs and the Evidence of History .