From 1946 the Vietminh fought heavily with France. They fought using Guerrilla warfare and this suited the environment and gave the Vietminh the advantage.
In 1954 the Vietminh defeated the French In the battle of Dien Bien Phu. This caused the French to leave Indo-China. The Geneva peace agreement led to the temporary partition of Vietnam. Elections were to be held in1956 in which the Vietnamese could vote for their leader.
The Vietminh leader Minh controlled North Vietnam and Bao Dai Controlled South Vietnam; he was disliked and was ousted by Diem.
Diem was a Nationalist and was supported by the Americans. Diem had no intention of holding the elections and stated that the communists would not allow free elections in the North. This broke the Geneva peace agreement and the USA supported his actions.
In order to keep peace in South Vietnam Eisenhower Sent in U.S Military advisors to help train the Vietnamese army in combat warfare, In 1961 Eisenhower left the office and by this time 685 advisors were in Vietnam.
Diem set up the South Vietnamese army and the new President Kennedy gave approximately $270 million to them. He sent up to 1000 advisors to help Diem. He did this due to the embarrassment of the Bay of Pigs and he wanted to retaliate for the building of the Berlin wall.
The United States was again fighting in the war for the wrong reason. They thought it was non-communist against communist. When in fact the peasants of Vietnam did not know what communism was and only followed the Vietminh as they helped them.
The involvement by the U.S up to 1963 had cost 50 American lives and more than $400,000,000 for a corrupt government. The South Vietnamese army would not fight for their country and the guerillas had taken over all the countryside. The U.S had to get out of Vietnam or take control and win the war.
Kennedy disliked Diem, as he was a bad leader and a bad name for America but he had to support him as they fought communism.
In November 1963 the South Vietnamese army officials assassinated Diem, as they were afraid that the US would withdraw support if Diem stayed in power. President Kennedy knew of the assassination but did nothing. A few weeks later Kennedy himself was assassinated but the assassinations were not connected.
The new president, Johnson had the opportunity to pull the US out of involvement in Vietnam he choose not to, he in fact increased the involvement as not to look weak. He poured more money and bombed the Ho Chi Minh trail.
The result of this was an escalation in USA's involvement in Vietnam. The congress passed the 'Tonking resolution’, which was to take all necessary measures to win.
The next President Was Richard Nixon, Nixon knew that being in the Vietnam War was a major problem. He wanted peace in Vietnam and to save the lives of the American soldiers. Nixon introduced a policy of vietnamisation, which encouraged the South Vietnamese to take responsibility for fighting the war. In June 1969 Nixon enounced the first of the U.S troops withdrawals. The 540,000 US troops were to be reduced by 25,000. Another 60,000 were to leave the following December.