The Vietnam War occurred between 1959 and 1975 in Vietnam, Laos, and Cambodia. It began as a result of the US strategy to prevent the spread of communism. There were two main power blocs involved - the US and allies who supported South Vietnam, and the Soviet Union and North Vietnam who wanted to reunify Vietnam under communist rule. The war resulted in nearly 60,000 American deaths and an estimated 2 million Vietnamese deaths, and Vietnam was ultimately unified under communist control.