American troops arrive in Korea to partition the country

1945 US troops arrive in Japanese-held Korea to partition the country. From the article:

"American troops arrive in Korea to partition the country
U.S. troops land in Korea to begin their postwar occupation of the southern part of that nation, almost exactly one month after Soviet troops had entered northern Korea to begin their own occupation. Although the U.S. and Soviet occupations were supposed to be temporary, the division of Korea quickly became permanent.

Korea had been a Japanese possession since the early 20th century. During World War II, the allies–the United States, Soviet Union, China, and Great Britain–made a somewhat hazy agreement that Korea should become an independent country following the war. As the war progressed, U.S. officials began to press the Soviets to enter the war against Japan. At the Yalta Conference in February 1945, Soviet leader Joseph Stalin pledged that his nation would declare war on Japan exactly three months after Nazi Germany was defeated. A few months later, at the Potsdam Conference in July and August 1945, it was agreed that Soviet troops would occupy the northern portion of Korea, while American forces would take a similar action in southern Korea in order to secure the area and liberate it from Japanese control. The occupations would be temporary, and Korea would eventually decide its own political future, though no date was set for the end of the U.S. and Soviet occupations. On August 8, the Soviets declared war on Japan. On August 9, Soviet forces invaded northern Korea. A few days later, Japan surrendered. Keeping to their part of the bargain, U.S. forces entered southern Korea on September 8, 1945.

Over the next few years, the situation in Korea steadily worsened. A civil war between communist and nationalist forces in southern Korea resulted in thousands of people killed and wounded. The Soviets steadfastly refused to consider any plans for the reunification of Korea. The United States reacted by setting up a government in South Korea, headed by Syngman Rhee. The Soviets established a communist regime in North Korea, under the leadership of Kim Il-Sung. In 1948, the United States again offered to hold national elections, but the Soviets refused the offer. Elections were held in South Korea, and Rhee’s government received a popular mandate. The Soviets refused to recognize Rhee’s government, though, and insisted that Kim Il-Sung was the true leader of all Korea.

Having secured the establishment of a communist government in North Korea, Soviet troops withdrew in 1948; and U.S. troops in South Korea followed suit in 1949. In 1950, the North Koreans attempted to reunite the nation by force and launched a massive military assault on South Korea. The United States quickly came to the aid of South Korea, beginning a three-year involvement in the bloody and frustrating Korean War. Korea remains a divided nation today, and the North Korean regime is one of the few remaining communist governments left in the world."