USS Iowa (BB-61) 1948, as part of the post World War II drawdown of the armed forces, "Iowa" was deactivated at San Francisco, and then formally decommissioned into the United States Navy reserve fleets on 24 March 1949. In 1950, North Korea invaded South Korea, prompting the United Nations to authorize military intervention. President Harry S. Truman ordered US forces stationed in Japan to transfer to South Korea. Truman also sent US based troops, tanks, fighter and bomber aircraft, and a strong naval force to the area to support South Korea. As part of the naval mobilization, "Iowa" was reactivated on 14 July
North Korea–South Korea relations led to the formation of the United Nations Temporary Commission on Korea (UNTCOK) in 1947. The Soviet Union opposed this move and refused to allow UNTCOK to operate in the North. UNTCOK organised a general election in the South, which was held on May 10, 1948. The Republic of Korea was established with Syngman Rhee as President, and formally replaced the US military occupation on August 15. In North Korea, the Democratic People's Republic of Korea was declared on September 9, with Kim Il-sung, as prime minister. Soviet occupation forces left the North on December 10, 1948. US forces left