During the Korean War the North Korean troops took over almost the whole Korean peninsula. Only due the US led UN troops intervention did the South Korean survive. After Some back and forth fighting with the US + South Korean troops agains North Korean + Chinese troops did the border stabilize where it stands today. US troops remain in South Korea as a deterrant against Norths invasion and to uphold the peace in the peninsula.
The US sent troops into Korea from Japanese military bases where US troops were stationed to help South Korea resist the North Korean invasion . The intervention of Chinese troops widened the war .
The Communist invasion of South Korea.North Korea's invasion of South Korea
28,000
westmoreland
UK, Turkey, Australia, South Korea had the most troops
South Korea to settle the republic of Korea
About 37 thousand.
The US was a main contributor in sending troops over to South Korea. The entire UN support was also led by US General Douglas MacArthur, whose brilliant military strategy at the Landing of Inchon kept South Korea from being overrun by the North.
They were sent into South Korea at the request of the United Nations to protect Sout Korea and to eject the invading North Koreans.
US involvement in the Korean War began with troops deployed to Korea in September of 1945. On July 5, 1950 US troops formally began to fight on South Korea's behalf. The battle of Osan was a decided defeat for our troops.
The US is not permitted to patrol North Korea, nor do they. The US military does however have military bases in south Korea as part of a treaty to protect them against a possible attack by North Korea.
the United Nations forces, which protected South Korea from an invasion by North Korea.