Korean War

Page 2 – Background

Because of its geographical position, pointing like a dagger at Japan, the Korean peninsula has always had great strategic importance. Its significance was hidden for 1000 years while China was generally the dominant power in East Asia, but the rise of Japan and the emergence of a Russian presence in the Far East in the 19th century changed the picture. In 1910 Japan annexed Korea.

That two Korean states existed in 1950 was an outcome of arrangements for the surrender of Japan in August 1945 which had resulted in the entry of both Soviet and American forces onto the peninsula. The ostensible purpose of this deployment was to take the surrender of Japanese troops, but both great powers were determined to maintain a foothold in the area. The demarcation line running along latitude 38° North was rapidly transformed into a quasi-border as relations between the Soviet Union and its former wartime allies worsened with the onset of the Cold War, with both sides encouraging sympathetic local political factions.

Partition became inevitable when negotiations for a unified Korean administration broke down. In 1948 the United Nations oversaw the creation of the Republic of Korea (ROK) in the south, with Syngman Rhee as president. The Russians responded by establishing the Democratic People’s Republic of Korea (DPRK) in the north, with Kim Il-sung at its head. Koreans were unreconciled to this outcome, and on both sides of the 38th parallel there was determination to reunify the peninsula. Border incidents were common.

The June 1950 invasion was initiated by Kim Il-sung, but Josef Stalin's approval was crucial and Soviet assistance in the form of arms and advice was provided to the Korean People’s Army (KPA). Catching the South Koreans by surprise, the KPA made rapid progress, capturing the southern capital Seoul within three days. With the United States to the fore, the United Nations Security Council urged a withdrawal, and when this demand was ignored it called on members to assist South Korea. Early in July it set up a UN Command, responsibility for which was delegated to the United States. General Douglas MacArthur, the Supreme Commander, Allied Powers in Japan, was appointed as Commander-in-Chief, UN Forces in Korea.

How to cite this page

'Background', URL: https://nzhistory.govt.nz/war/korean-war/background, (Ministry for Culture and Heritage), updated 19-Oct-2022