KOREAN WAR The Korean war began after the second world war when Korea was divided (as it still is (1995)) into Communkst North Korea and the U.S backed South Korea. North Korean troops invaded South Korea and advanced on Seoul. United Nations troops and South Korean troops halted them, but soon the Chinese entered the conflict. The war howver did not escalate to a general world conflict as was feared a the time and eventually, the Reds withdrew and an armistice was signed.