Answer:
The winds of the Cold War blew very strongly in Asia and in the world. The US had sent its forces to Korea to stop what it saw a move of communist expansion and aggression in the 1950s.
It was a reaction that followed the tenets of the containment doctrine that said that the US should employ military, economic and diplomatic means to contain the Soviet Union and the expasion of communism around the world. Besides, the Eisenhower administration had adopted the domino theory, which held that if one country of Asia fell into communist hands, other countries in the region would follow soon.
After the French military defeat in 1954 by communist Vietnamese forces and the end of colonial rule in the mid-1950s, the USA took a larger role in Southeast Asia. The Geneva Accords called for nationwide elections in Vietnam, but fears of a communist victory made Washington opt for not holding the vote. The main goal of American political and military engagement in the Vietnamese civil war to support the pro-Western South Vietnam was the same as in Korea: to stop the expansion of communism. After the 1964 Gulf of Tonkin incident, the US escalated its military presence in Vietnam. In 1965, there were over half a million US troops there.
Explanation:
