The War It all started when North Korea began to invade South Korea. South Korea knew that North Korea was moving into their country, so they contacted the United States for help. The United States sent over General Douglas MacArthur. MacArthur was able to push back North Korea from taking over South Korea. The United States was also able to push them to the border of China. When this had happened, the US and South Korea were pushed back to the 38th Parallel. By the end of the war, approximately 4,000,000 Koreans were killed, and only 50,000 US troops were killed.
Before the War: Leader Mao Zedong put the Peoples Republic into place in China, and was allied with the Soviet Union. China touched the borders of North Korea, so it only made sense that North Korea became influenced into becoming communist as well. From this, South Korea and the United States started to become afraid, since they feared that the "Domino Effect" would take place.