The Foreign Interventions_The Cold War
Due to the fact that the Korean War occurred during the Cold War era with the direct military engagement of the US and USSR, the Korean conflict can be seen as a continuation of the United States and the USSR’s rivalry for their imperialism.
Post World War II, both United States and USSR did not want any military aggression to occur as they were tired of any more fights. Thus the two powers began to compete each other through the conflicts of foreign countries, in order to spread their own power more globaly; examples are Vietnamese War and Cuban Missile Crisis. Likely, the influence of Cold War tension on the Korean conflict cannot be ignored.
When the United States settled a US military government in South Korea, a State Department official wrote in September 1947, that he “fears” that US abandonment of Korea “will be interpreted throughout the world as an indication that the United States has decided not to maintain its strong position in the Far East. The result upon Soviet policy toward the United States, both [in] the Far East and […] in Europe would […] be unfortunate.” The United State’s intention on Korea was clear as they strongly showed their will to go against communism in Korean Peninsula, and the Americans viewed the civil conflict in Korea more as a conflict between themselves and the Soviets, figthing for expansion of their social ideology. Prior to the Korean War, the United States government was criticized for the “lost” of China as China fell to the hand of communism. The United States feared the expansion of communism in Asia and Harry S. Truman, who was the president of United States at the moments, expresses his emphasis on securing South Korea in one of this letters.
Below image is by a British cartoonist David Low, published in the Daily Herald on June 30th, 1950. It shows Truman and the United Nations rushing to Korea's aid.
US's concern for the spread of communism can be observed through the State's direct military involvement. When the South and the UN army managed to fight back to the North, they almost approached toward the Manchurian border. The South's chief military commander at that time - General MacArthur - wished to march into China as well and this shows the US's strong desire to get rid of communism. Below quotation shows how the US viewed the Korean War as a fight with communism:
"The UN gave the USA unlimited authority to direct military operations. US president Truman, not the UN, appointed General MacArthur as commander-in-chief of UN forces. MacArthur reported to the US President and took orders from him. The war threatened to become one between the USA and China. The USA even considered using nuclear weapons against China."
This video shows an opinion of a Chinese veteran of the Cold War on his view of foreign engagement in the Korean War.
The reason for the Americans to unilaterally divide the Korean Peninsula in half was to prevent anymore spread of communism in Korea. They wanted to at least secure the South as they feared the entire peninsula being engulfed by the red army. The United States’ motivation to divide Korea and establish a military government derived from their rivalry toward USSR. How the wave of the Cold War influenced over Korea must be included when studying the origins of the Korean War.