In this introduction, leading Vietnam War historian Dr Andrew Wiest provides a concise overview of America's most divisive war. America entered the Vietnam War certain of its Cold War doctrines and convinced of its moral mission to save the world from the advance of communism. However, the war was not at all what the United States expected. Dr Andrew Wiest examines how, outnumbered and outgunned, the North Vietnamese and Viet Cong forces resorted to a guerrilla war based on the theories of Mao Zedong of China, while the US responded with firepower and overwhelming force. Drawing on the latest research for this new edition, Wiest examines the brutal and prolonged resultant conflict, and how its consequences would change America forever, leaving the country battered and unsure as it sought to face the challenges of the final acts of the Cold War. As for Vietnam, the conflict would continue long after the US had exited its military adventure in Southeast Asia. Updated and revised, this is an accessible introduction to the most important event of the "American Century."