Editors Note: We're blogging through We Didn't Start the Fire by Billy Joel.
Japan officially added Korea to its territories in 1910. They used Korea’s resources in WWII, including 2.6 million forced laborers. After losing the war, they turned it over to both the Soviets and the Americans, who had an agreement in place to jointly occupy it. The USSR was to occupy the northern part of the country - north of the 38th parallel. The US would occupy the south. After splitting up the country, they agreed to free Korea after 5 years - without consulting the Koreans over anything.
On September 23, 1950, the railway workers went on strike, triggering civil unrest across the country. In one attack, 3 police officers were killed, with 40 more injured. The US, realizing the danger, set up elections to make the country free immediately. This angered the Soviets, who insisted on the 5 year plan. The result was a communist government in the north, and a democracy in the south.
In June 1950, North Korea invaded South Korea, backed by Soviet support. The US, backing South Korea, were caught unprepared. The US quickly formed a water-and-air-only plan, thinking the North Korea forces could be halted quickly. This was quickly found incorrect, and the United Nations agreed to put troops on land. In late 1950, China also came to the aid of North Korea, strengthening them with troops and supplies.
In November of 1954, both sides agreed to an armistice, causing both sides to come to a cease-fire. This lasted all the way until 2013, when North Korea invalidated the armistice. While nothing drastic has happened yet, the Korean War is not over.