The Korean War (June 25, 1950 - July 27, 1953) was an armed conflict in the Korean region fought between North Korea (the Democratic People's Republic of Korea; DPRK) and South Korea (the Republic of Korea; ROK) and their allies. North Korea was supported by the People's Republic of China and the Soviet Union, while South Korea was supported by the United Nations Command (UNC) under the leadership of the United States. The war ended in 1953 without the signing of a peace treaty.
The Korean War lasted from 1950 to 1953, during which communist North Korea (supported by China and the Soviet Union) fought against anti-communist South Korea (backed by the United States).
The war began when North Korean forces crossed the 38th parallel, the line dividing North and South Korea that was established after the defeat of the Japanese invaders in World War II.
Under President Harry Truman, the United States entered the war to defend South Korea based on the Truman Doctrine. The United Nations also provided support, but the U.S. supplied 90% of the troops. After initial successes by North Korea, American forces pushed North Korea back. When American forces crossed into and entered North Korea, China sent its military forces to aid North Korea.
Subsequently, American and South Korean forces were pushed back before later regaining ground. Initially, President Truman did not want to escalate the war, fearing the start of a wider conflict, and began peace talks with North Korea in July 1951.
The peace talks concluded with an armistice signed in July 1953, which halted the war, reinforced the division of the two Koreas along the 38th parallel that separated them, and established a 4-kilometer-wide Demilitarized Zone.
Nearly five million people died in the war, while over 2.7 million civilians were injured, and more than 30,000 Americans died.