In practice, MacArthur controlled land operations through "task forces". These reported directly to GHQ, and their commanders could control all Allied land, air, naval and service forces in their area if a Japanese land attack was imminent. The most important of these was New Guinea Force, which was formed in 1942 and was commanded personally by Blamey in September 1942, and again in September 1943. In February 1943, Lieutenant General Walter Krueger's Sixth Army arrived in SWPA, and its headquarters became that of Alamo Force. Alamo Force reported directly to MacArthur, and as a result Blamey did not command of the majority of American land forces in the theatre after that time, although his post was not abolished.