The third and final volume of The Cambridge History of the Vietnam War examines key domestic, regional, and international developments in the period before and after the war’s end, including its legal, environmental, and memorial legacies. The latter stages of the Vietnam War witnessed its apex as a Cold War crucible. The Sino-Soviet dispute, Sino-American rapprochement, Soviet–American détente, and global counterculturalism served in various ways to elevate the already high profile and importance of the conflict, as did its expansion into Cambodia and Laos. After the “fall” of Saigon to communist-led forces and Vietnam’s formal reunification in 1975–6, Hanoi’s persecution of former enemies, discrimination against ethnic Chinese, and economic mismanagement triggered a massive migratory crisis that redefined international refugee policies. In time, the migration changed the demographic landscape of cities across North America and Europe and continued to impact our world long after the conflict ended.