Wars (battles) are dictated by terrain. Korea was a peninsula and was easily isolated, as the US Navy controlled the seas. Communist North Korea could only re-supply from it's northern borders. Vietnam was NOT a peninsula, and could re-supply their war effort for as long as they wanted to. The only way to defeat them would have been to widen the war and involve other countries, in order to stop their flow of men and material into South Vietnam. The US did NOT want to make a bigger war. So we ended it, by leaving.
U.S. forces successfully defended South Vietnam from the time they entered the country in 1959 through 1973 when they left. They perfected helicopter warfare against guerrilla tactics.
The U.S. had total air and sea dominance in the south as well.
South Vietnam fell to the North Vietnamese communist forces a full two years after the U.S. left Vietnam.
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The terrain and weather were a big factor as Viet Congs were believed to be more skilled in jungle combat (their home land advantage?). Plus, Vietnam got the necessary support from China.
After the US withdrew from Vietnam the Vietcong came into power. South Vietnam fell under communist rule by the Vietcong.
the Us and Vietnam government
Communist NORTH Vietnam wanted to re-unite with it's SOUTHERN half; SOUTH Vietnam. The US backed South Vietnam desired to remain a non-communist Republic of South Vietnam. Because the "Communists" were involved, and this was the cold war era; the US had to stop & contain communism. The North attacked the South, the South resisted...Vietnam War.
Besides the US; Australia, New Zealand, South Korea, Thailand, and the Philippines sent COMBAT units to Vietnam.
The US was supporting South Vietnam. The US opposed the communist North Vietnam, which was led by Ho Chi Minh. South Vietnam was ruled by President Diem (pronounced like Z-M) who was later assassinated by South Vietnam rebels.The people of South Vietnam rebelled against Diem because he was Catholic and tried to change the people's religion form Buddhism to Catholicism. Kennedy and everyone saw the pictures of the Buddhist monks setting themselves on fire and it leaked out that the US favored a coup (pronounced like coo) and the takeover by other officials led to the assassination of Diem.Kennedy also funded a CIA operation which encouraged the overthrow, and indirectly ended in Diem's assassination.
South Vietnam was considered an ally of the US.
The successful coup was in '63 & supported because Diem had to go.
South Vietnam
USA lost to north Vietnam not south. The south was their ally.
South (RVN-Republic of South Vietnam)
North Vietnam started the war against South Vietnam; the US went to the aid of the South.
The US didn't invade South Vietnam. The Republic of South Vietnam asked for US help as they couldn't stem the Red Tide (communist infiltration).
There IS no North and South Vietnam, only Vietnam. After the US withdrew combat forces from South Vietnam, North Vietnam violated the peace agreement, invaded and conquered South Vietnam. Game over.
US, New Zealand, Australia, South Korea, South Vietnam, Thailand, Philippines.
north Vietnam took over south Vietnam
The US was an ally of South Vietnam; it was up to South Vietnam to repel the invasion from the north, with massive military assistance from the US (which, of course, ultimately failed).
Simple, the US.