Walton Walker backed South Korea, and China allied with the Soviet Union in what was to become the first military action of the Cold War. Shortly after 75,000 North Korean troops with tanks invaded South Korea on June 25, 1950, American air and sea forces were ordered by President Harry S. Truman to give South Korean troops support. The U.S. Eighth Army was ordered to intervene and drive the invaders back across the 38th parallel, the border between the two countries. With only four lightly equipped and poorly trained divisions, Walker began landing troops on the southeast side of the Korean peninsula
South Korea apply since 2011. In addition to male conscription in South Korea's sovereign military, 1,800 Korean males are selected every year to serve 21 months in the KATUSA Program to further augment the United States Forces Korea (USFK). In 2010, South Korea was spending ₩1.68 trillion in a cost-sharing agreement with the US to provide budgetary support to the US forces in Korea, on top of the ₩29.6 trillion budget for its own military. The South Korean army has 2,500 tanks in operation, including the K1A1 and K2 Black Panther, which form the backbone of the South Korean army's mechanized armor