Causes of the Korean War (AQA GCSE History): Revision Note

Summary

The Korean War was part of a broader conflict known as the Cold War. This was a conflict that began at the end of World War II and was between the USA and its allies and the USSR and its allies. After Nazi Germany and Japan had been defeated, the USSR and the USA, who were allies during World War II, became known as superpowers and were locked in a struggle for global domination.

The two superpowers were organised in very different ways and followed different ideologies. 

The USA was a capitalist country that allowed private ownership of land and businesses. This led to some people becoming extremely wealthy and others becoming very poor.

The USSR was a communist country, where the state owned all property and means of production. All wealth was then to be shared, which was intended to create a more equal society. 

When the USA defeated the Japanese and German forces and liberated a country, a capitalist economy was created, and that nation became an American ally. When the USSR liberated a country from Germany or Japan, a communist government was installed that was loyal to Moscow. This meant that, from 1945, the world was divided into capitalist countries that were loyal to the USA, communist countries that were loyal to the USSR and non-aligned countries that were loyal to neither. When there was a conflict within a country over whether to become capitalist or communist, the USA and the USSR became involved. This is what happened in both Korea and Vietnam.

Korean nationalism

• Nationalism also played a key role in causing the Korean War

  • Korea had a long history of being occupied by other countries and had been ruled by Japan from 1910 until the end of World War II in 1945

  • Most Koreans hated living under Japanese rule and were desperate to create a free and independent Korea

  • The Japanese brutally suppressed the Korean nationalists, and many thousands were killed

• In response to the Japanese brutality, many Korean nationalists fled north to China

  • Some established an independent Korean government in exile that was ready to step in once the Japanese had been overthrown

  • Others trained to become guerrilla fighters with the Chinese communists and started to attack the Japanese troops

The division of Korea

• After Hitler’s death and Germany’s defeat, the leader of the USSR, Josef Stalin, declared war on Japan on 8th August 1945

  • His troops swooped into Korea and liberated the north of the country from the Japanese

• The USA feared that Stalin was launching a land grab in Asia in the same way it believed he had in Europe

  • All of the countries in Europe that Stalin’s troops liberated from Nazi Germany became communist allies of the USSR

  • The USA believed there was a danger of the same thing happening with Korea 

  • It quickly sent troops to liberate the south of Korea and suggested dividing the country in half to Stalin

• Stalin was wary of fighting the USA in Korea in 1945

  • His forces were outnumbered in the region, and the USA had the newly developed atomic bomb

  • Stalin agreed to split Korea along the 38th parallel 

  • This meant 9 million Koreans to the north of that line would remain under the control of the USSR

  • The capital city of Seoul and around 16 million Koreans were to the south of the line and came under the control of the USA

• It was agreed that elections would be held at a future date to form the government of an independent and united Korea

Leadership of Kim II Sung and Syngman Rhee

• The elections to form a government to govern all of Korea never took place

  • By 1948, relations between the USA and the USSR had worsened and trust had broken down completely

  • The USA then organised elections for the south of the country, which resulted in the formation of the Republic of Korea (ROK), or South Korea, in August 1948

  • The USSR responded by supporting the creation of the Democratic People’s Republic of Korea (DPRK), or North Korea, in September 1948

  • There were now two Koreas

• The leader of the DPRK in the north was Kim Il Sung

  • He was a committed communist and Korean nationalist

  • As a child, he fled to China with his family to avoid the Japanese occupation

  • He fought in the USSR’s Red Army against the Japanese, rising to the rank of major, and lived in the USSR for a time

  • His communist beliefs and loyalty to the USSR won him the support of Stalin

  • Stalin supported Kim Il Sung both politically and by sending tanks, weapons and equipment for his army

  • Kim II Sung was also very popular with many desperately poor peasants because he stripped the land from rich landowners and gave it to the poorer people

• The leader of the ROK in the south was Syngman Rhee

  • He was elected as leader, but many historians question how fair and free those elections were

  • He was a Korean nationalist and fiercely anti-communist

  • His fears of a communist takeover led him to round up those he suspected of being communists and to suppress free speech

  • This led to him being unpopular with the Korean people, but he maintained the support of the Americans

  • The Americans valued his anti-communist stance, although they refused to aid him in his plans to attack the north 

North Korean invasion of South Korea

• Kim Il Sung had been eager to invade the south since 1948, but Stalin had refused to back him

• That changed, and on 25th June 1950, North Korean troops crossed the 38th parallel and invaded the south

• As the USA had not become involved in China’s civil war, Stalin was confident that it would also stay out of Korea

  • He agreed to supply tanks, aircraft and weapons to North Korea — but no troops

  • Around 70,000 North Korean troops who had been fighting for the communists in China returned home once the Chinese Civil War was over

  • China agreed to provide reinforcements if they were needed and moved troops to the North Korean border

• The south was unable to repel invaders that were equipped with tanks and aircraft

  • Within three days, Seoul, the capital of the south, had been captured

  • Within weeks, nearly all of South Korea was controlled by the communists

• The swift victory that the USSR and North Korea had expected seemed inevitable

  • The reaction of the USA caught them completely by surprise and changed everything