North Korea has been among the most vexing and persistent problems in U.S. foreign policy in the post-Cold War period. The United States has never had formal diplomatic relations with North Korea. Negotiations over North Korea's nuclear weapons program have consumed the past three U.S. administrations, even as some analysts anticipated a collapse of the isolated authoritarian regime. This book provides background information on the negotiations over North Korea's nuclear weapons program that began in the early 1990s under the Clinton Administration. Although negotiations have reached some key agreements that lay out deals for aid and recognition to North Korea in exchange for denuclearization, major problems with implementation have persisted. With talks suspended since 2009, concern about proliferation to other actors has grown.