Setting Up the United Nations Organisation and Its Work to 1964 » The UN and the Korean War, 1950-53

Why was there a war in Korea?

At the end of the Second World War, Korea was split at the 38th parallel, a line of latitude across the country. Soviet troops held the north and American troops held the south. By 1948 there were two separate states: communist North Korea, led by Kim Il Sung, and South Korea, led by Syngman Rhee. Each claimed to be the government of the whole of Korea.

On 25 June 1950 North Korean forces crossed the 38th parallel and invaded South Korea. Seoul, the southern capital, fell within days.

Key terms:

• 38th parallel: the line that divided North and South Korea.
• Boycott: refusing to take part in something as a protest.
• Ceasefire: an order to stop fighting.
• Uniting for Peace: a General Assembly resolution of 1950 that let the Assembly act when the Security Council was blocked.

The Security Council acts

The Security Council has five permanent members, and any one of them can use the veto to block a decision. In January 1950 the USSR began a boycott of the Council. It was angry that the seat for China was held by the Nationalist government on Taiwan, not by the communist government that ruled the mainland. So when North Korea invaded, the Soviet seat was empty and nobody could use its veto.

This was the first time the UN used armed force against an aggressor. Sixteen countries sent fighting troops, including Britain, Canada, Australia and Turkey, and others sent medical teams. The force fought under the UN flag, and the American General Douglas MacArthur was its commander. The USA supplied most of the foreign troops, and South Korea's own army was also large.

The Soviet Union returned to the Council in August 1950 and called the vote illegal, but it was too late to undo it.

The course of the war

At first the UN forces were pushed back into a small corner of the south. In September 1950 MacArthur landed troops at Inchon, behind the North Korean army, and drove it back. UN forces crossed the 38th parallel in October and advanced towards the border with China. Then China entered the war on the North's side, and by early 1951 the UN forces had been pushed back south again. After that the fighting settled near the 38th parallel.

Uniting for Peace

With the USSR back on the Council, the veto could now block any further action. The USA and its allies therefore turned to the General Assembly, where there is no veto. On 3 November 1950 the Assembly passed the Uniting for Peace resolution. It said that if the Security Council could not act because of a veto, the Assembly could meet within 24 hours and recommend action, including the use of force. The Assembly's decisions were only recommendations, but it was a new way round the veto.

The armistice

Two years of talks followed while the fighting continued. An armistice, an agreement to stop fighting that is not a peace treaty, was signed at Panmunjom on 27 July 1953. The border was set close to the 38th parallel, with a demilitarised zone on each side of it. No peace treaty was ever signed, so the two Koreas have stayed divided.

What did Korea show about the UN?

Changed: unlike the League, which had no army, the UN fought a war to defend South Korea. Stayed the same: action still depended on the Great Powers agreeing, and the UN could not end a war once China had joined in.

Exam-style question

Explain TWO ways in which the response of the UN to the invasion of South Korea in 1950 was different from the response of the League of Nations to the Japanese invasion of Manchuria in 1931. [6 marks]

(Remember that in 1931 Japan invaded the Chinese region of Manchuria, and the League sent a commission of enquiry.) You must give two ways. One way alone can score no more than half marks.