The Vietnam War, also known as the American War, and the Second Indochina War began in December 1956. 58,000 Americans were killed. The war ended on April 30, 1975, with the withdrawal of the United States Army and the reunification of South and North Vietnam. The United States government, led by Lyndon Baines Johnson, tried to prevent the spread of communism in North Vietnam, because if Vietnam became a communist country, neighboring countries, such as Laos, Thailand, and Cambodia might be affected and become communists as well. they communist countries. like a domino, gradually rejecting countries that agree to be communist, called the "domino theory". On the other hand, South Vietnam was a capitalist country. In 1965, the U.S. Army flew 8,000 miles and landed in South Vietnam to fight communism. North Vietnam was supported by the USSR, Russia. There are many ways the Vietnamese army, known as the Vietcong, used to win the war and force the US army to retreat. In 1969, when Richard Nixon became the new president, he began working to remove troops from Vietnam. In 1973 the peace talks held in Paris finally ended and the US army backed down. There are also many flaws of the US military that will end up losing the war. The main factors are each country's tactics, popular support from its home country, weapons, supplies and resources, and finally, the confidence and motivation of soldiers in war. So what was the main reason that answers the question: why was the US Army forced to withdraw from Vietnam and what is the most important? The different weapons, supplies and resources are one of the factors that affected both armies. First, because America was the richest country in the world… middle of paper… This is because their tactics, such as bombing and spraying deadly chemicals, are harmful and destroy the planet's environment. local citizens of Vietnam, while America went all the way to persuade North Vietnam to be a capitalist instead of a communist. By damaging people's food and lives, America had lost the support of the Vietnamese people, who changed, to support the Viet Cong, communism, which could have affected how the Viet Cong fought the United States again. Popular support is the second, and trust is the third, because the tactics affect them, having inadequate tactics, you lose hope in your army and, therefore, the soldiers become demoralized and lose confidence. The weapons are the least important, because they have better equipment than Vietnam, but it was the tactics that misused them and wasted money and time spent on being sent to Vietnam.