The Korean War


  • In 1949, China became communist after a long civil war. Support for the communists had increased due to corruption, high taxes, food shortages and a desire for land. Mao Zedong had led the communists to defeat the Nationalist Government of Jiang Jieshi (Chiang Kai-shek) who had been backed by American Financial Aid.

  • American spies had also informed Truman that Stalin was using cominform to help communists in Malaysia, Indonesia, Burma, the Philippines and Korea to take control.

  • The Government was very anxious as the USSR had recently successfully tested an atomic bomb. The US feared that the Soviets wished to take over the entire continent of Asia!

Korean Crisis

  • Until 1945, the Japanese Empire ruled over the Korean peninsula. At the end of WW2, the North of Korea was liberated by the Red Army, while the South was liberated by the US.

  • The Soviets helped Kim Il Sung's Communist Government to take control of the North, while the US supported Syngman Rhee's anti-communist government. Although the government was very corrupt and undemocratic, the US supported it due to it's anti-communism.

  • Korea became divided at the 38th parallel and both leaders were very hostile towards each other.

  • North Korea used a surprise attack and invaded South Korea which overwhelmed their army.

  • By September of 1950, the South Korean army had been pushed back to Pusan, a small area on the Southern Tip of Korea.

Why would Truman want to get involved?

  • He is very anti-communist and wants to contain it.

  • There is open warfare and he wants to prevent another war.

What problems arose and how did the US react?

  1. North Korean forces invaded South Korea and conquered all but the Pusan area of South Korea. The US responded by taking the issue to the UN security council. At this time, the USSR couldn't veto any actions as they were boycotting the United Nations. As a result, the UN sent forces (mainly US troops) to Korea.

  2. The UN Army was led by General MacArthur, a world war two veteran, who planned a counter attack to push out the North Koreans with land offense and an amphibious assault behind enemy lines. Truman backed MacArthur's plan and it was successful. The UN forces were able to take control of the South Korean capital within 4 days and had reached the border by October 1st.

  3. By the 1st of October, UN soldiers had reached the 38th Parallel. Truman had to decide whether to invade North Korea or stop at the border. However, this could result in Chinese intervention. MacArthur persuaded Truman to order the troops to advance. By October 7th, the troops had reached the Yalu River near the Chinese border, deep inside North Korea.

  4. China warned that they would enter the war if the UN soldiers continued their advances. However, the US ignored their warning, and China crossed the Yalu river.

  5. UN forces were forced to retreat while French and British leaders asked for the US to negotiate a peace settlement to end the war. MacArthur planned a new counter attack which failed. North Korea took over Seoul and regained North and much of South Korea.

  6. General MacArthur continued to ask for further action, while British Prime Minister Clement Attlee was persuading Truman to end the war. Again, Truman agreed with MacArthur's counter attack, and this time is was a success, pushing North Korean and Chinese forces back to the 38th Parallel.

  7. Now Truman had began to agree that a peace settlement was necessary. MacArthur wanted to continue fighting and criticised Truman and the idea of a peace settlement with China. As he was ignoring Truman's order, he was dismissed. Peace settlements were negotiated and the war ended. To this day, North Korea still claims that it won the war.

How successful was the US in Korea?


  • The war had shown that the US was not invincible. Chinese and North Korean forces had been able to inflict several defeats and many casualties on the UN army.

  • The USSR had realised that it should never boycott the UN Security Council again as it was clear that the power of veto was important in blocking US attempts to stop the spread of communism.

  • The US policy of "Roll Back" had been a failure and was criticised by many of America's allies.


  • The war lead to the creation of SEATO (South East Asian quivilant of NATO)- an anti-communist military alliance

  • The US had prevented South Korea from becoming communist and it became an important anti-communist ally in Asia.

  • The war had shown American commitment to containing communism in Asia, which was a warning to other communist rebels.