In the 1960s, not only was a great cultural shift taking place, but the world in which it took place was also a dangerous one. The cold war was at its height during the Cuban missile crisis, and the thing preventing the United States and the Soviet Union from actually starting a war was the idea of a nuclear holocaust. During the 1980s many now Soviet leaders came to power in quick succession, because of the politburos propensity for electing sickly elderly men as leaders of the Soviet Union. Leaders Andropov and Gorbachev wanted to better the economy and living situation for the Russian people without getting rid of communism. Andropov was also someone who was a complete Soviet insider who had once been the leader of the KGB. He wanted the world to know that the Soviet Union was not to be reckoned with, which lead to Soviet Fighters shooting down flight KAL-007.
The Vietnam war officially started in 1955 when the French withdrew from their former colony and communists took over the Northern part of Vietnam. The United States began with a low level of intervention in the Vietnam war, such as sending supplies and ammunition. The Ruler of South Vietnam Ngô Đình Diệm was a Catholic and made himself very unpopular with failed land reforms and acts against Buddhism in a largely Buddist country. In 1963 the CIA told generals planning to remove Diệm, that they would not punish them by cutting off aid. Therefore on November 2, 1963, Diệm and his brother were killed in a coup and twenty days later President Kennedy was assassinated. During his presidency, Kennedy had escalated US involvement in Vietnam but was against the deployment of troops. During the Johnson administration, many troops were deployed and involvement in Vietnam became a full-on war until the last troops were pulled out in 1975.
*By Enterprises, I meant the ones mean the ones Captained by James T. Kirk and Jean-Luc Picard.