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
Tanks of South Korea its inferior mobility, and in November, 1949, the upgraded M26 received a new power plant and a main gun with bore evacuator, and the M46 Patton designation. Less than a thousand were upgraded to M46 standard. On 8 August 1950 the first M46 Pattons landed in South Korea. The tank proved superior to the much lighter North Korean T-34-85, which were encountered in relatively small numbers. By the end of 1950, 200 M46 Pattons had been fielded, forming about 15% of US tank strength in Korea; the balance of 1,326 tanks shipped to Korea during 1950 included 679 M4A3 Shermans,