North Korea possesses nuclear weapons, while Iran is poised to acquire them in the next decade. How the United States and other nations seek to roll back these burgeoning nuclear powers is among the most urgent issues of the day. At stake is regional security in the Persian Gulf and Northeast Asia, America's standing abroad, and prospects for nuclear nonproliferation. The contributors to this volume offer complementary international perspectives on the critical security issues that stem from the challenges posed by Iran and North Korea. No other work combines the analysis of the two countries and explores the threat posed by each to regional stability and world order. The book examines how and why attempts to curb the nuclear programs and broader political ambitions of each nation have failed. It also examines how each nation, in its own way, has managed to defy the world's preponderant power, the United States, as well as other major powers and the United Nations. And it offers analysis on where the fractured and oscillating relations with these two nettlesome actors are heading and the long-term implications of their current trajectories for nuclear proliferation, deterrence, alliance management, regional security, and world order. Expert, balanced analyses--augmented by new chronologies and maps--make the volume an invaluable reference for all those interested in understanding the options available in dealing with Iran and North Korea.