Final answer:
The United States was involved in the Korean War to stop the spread of communism.
Step-by-step explanation:
The United States was involved in the Korean War to stop the spread of communism. The Soviet Union and China supported North Korea, while the United States along with its allies, including Japan, supported South Korea. The conflict was seen as a proxy war between the capitalist West and the communist East during the Cold War.
Learn more about The United States' involvement in the Korean War