With the Allied victories in Europe and Japan, Korea, which had been occupied by Japan since 1910, was placed under the temporary control of Russia and the United States. Korea was divided into two separate states at the thirty-eighth parallel, with Russia holding the North and America holding the South (Uschan 36). As the relationship between Russia and America worsened, leading to the Cold War, both attempted to gain as many allies as possible to support them (Bachrach 11). The American government felt it was their duty to stop the Soviet Union and issued the Truman Doctrine, which was a policy to fight communism throughout the world (Uschan 27). Thus US involvement in the Korean War was justified as a way to demonstrate that the US would not allow the Soviet Union to spread communism without fighting. After the events of World War II, the world was left with two great superpowers: the United States and the Soviet Union. Both sides of the conflict were balanced in power and nuclear war was possible. Most of the fighting was indirect and neither nation sent armed forces against each other (Smith 30). Since these nations were the world's superpower, they exerted great influence over other countries in the world and used foreign nations' conflicts as a way to challenge each other. America began to cultivate a fear of communism, known as the Red Scare, which would only intensify when China fell to communism (Helbertsam 587). Around 1947, South Korea was one of the few areas in Northeast Asia not under Communist rule (Bunge 22). . It began to appear as if the Soviets were gaining territory that they would likely never give up, causing U.S. officials to realize that they had to stake claims to part of Korea (Uschan 25). While under US and Soviet rule, North and South Korea were supposed to hold an election that would reunite them sometime after World War II. However, the Soviets prevented this and maintained control over North Korea (Williams 41). Eventually the United States and the Soviets began to form separate groups to take a unified position against each other, such as NATO and the Warsaw Pact, making unification even more unlikely between the two parts of Korea. On June 25, 1950, North Korea attacked South Korea. since the invasion was led by a communist force, it gave the U.