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
Air Battle of South Korea of June 25, 1950, ten divisions of the North Korean People's Army launched a full-scale invasion of the nation's neighbor to the south, the Republic of Korea. The force of 89,000 men moved in six columns, catching the Republic of Korea Army by surprise, resulting in a rout. The smaller South Korean army suffered from widespread lack of organization and equipment, and was unprepared for war. The numerically superior North Korean forces destroyed isolated resistance from the 38,000 South Korean soldiers on the front before it began moving steadily south. To prevent South Korea's collapse the United Nations Security Council