Causes of the Korean War
- The Korean War began due to Cold War rivalry, conflicting nationalisms, and competition between communist and capitalist states after 1945.
- Korea was divided along the 38th Parallel after Japan’s defeat, creating two rival states: communist North Koreaunder Kim Il Sung and capitalist South Korea under Syngman Rhee.
- Both governments claimed to be the sole legitimate government of all Korea, increasing tension and border clashes.
- The success of the Chinese Communist Revolution (1949) strengthened communist confidence in Asia.
- The Soviet Union encouraged Kim Il Sung’s ambitions, providing tanks, military training and strategic guidance.
- The United States supported South Korea to enforce containment and prevent communist expansion.
North Korean Invasion of June 1950
Motivations for the Attack
- Kim Il Sung believed the South was politically weak and militarily unprepared.
- He argued that Koreans wanted reunification under communism, portraying the invasion as a national liberation.
- The Soviets approved the plan, believing the US might not intervene directly.
- The recent communist victory in China emboldened North Korean leaders.
- Kim expected a quick victory before international reaction could mobilize.
Immediate Causes and Escalation
- Border clashes in 1949–1950 created a volatile frontier environment.
- Stalin gave limited but crucial support, including armor and intelligence.
- The US withdrawal of most troops in 1949 created a perception of American disengagement.
- North Korean forces crossed the 38th Parallel on June 25, 1950, overwhelming South Korean defenses.
- The speed of the invasion triggered urgent international action.
Definition
38th Parallel
Line dividing North and South Korea after 1945, becoming the frontline of political tension.
Definition
Containment
US policy aiming to stop the spread of communism.
Nature of the Conflict and International Responses
- The Korean War became a major Cold War battlefield, involving the United Nations, the United States, China and the Soviet Union, turning a civil conflict into an international war.
- The UN labeled the invasion a breach of peace and authorized a UN Command led by the US.
- Early UN forces were pushed into the Pusan Perimeter, nearly losing the peninsula.
- General Douglas MacArthur launched the dramatic Inchon Landing, turning the tide in favor of the UN.
- China entered the war after UN troops approached the Yalu River, fearing a hostile army on its border.
