provides a comprehensive examination of the U.S.-South Korea defense relationship from 1945 to the present. Using deterrence theory as its framework, this work explores the evolving nature of U.S. interests in a region that became a focal point only after the North Korean invasion in 1950. Author Terence Roehrig addresses the changing nature of the threats to U.S. interests in Korea, especially North Korea's buildup and its efforts to acquire nuclear weapons, and examines specific measures utilized by the United States to implement its deterrence policy. While U.S. policy regarding Korea has changed over the years, this timely and important work argues that although the U.S. commitment to protect its ally has been credible and effective the same cannot be said for its attempts to prevent North Korean nuclear proliferation. is certain to find an audience amongst scholars of defense policy, national security, and Korean security relations.