On 25 June 1950, North Korea invaded South Korea, starting the Korean War. The United Nations Security Council passed Resolution 82, which authorized a United Nations Command (UNC) force to assist South Korea. The UN empowered the American government to select a commander, and the Joint Chiefs of Staff unanimously recommended MacArthur. He therefore became commander-in-chief of the UNC, while remaining SCAP in Japan and Commander-in-Chief, Far East. All South Korean forces were placed under his command. As they retreated before the North Korean onslaught, MacArthur received permission to commit U.S. ground forces. All the first units to arrive could do was trade men and ground for time, falling back to the Pusan Perimeter. By the end of August, the crisis subsided. North Korean attacks on the perimeter had tapered off. While the North Korean force numbered 88,000 troops, Lieutenant General Walton Walker's Eighth Army now numbered 180,000, and he had more tanks and artillery pieces.