In preparation for the invasion, MacArthur activated the US Army's X Corps to act as the command for the landing forces, and appointed Major General Edward Almond, his chief of staff, as Corps' commander, anticipating the operation would mean a quick end to the war. Throughout August, MacArthur faced the challenge of re-equipping the 7th Infantry Division as it had sent 9,000 of its men to reinforce the Pusan Perimeter and was far understrength. He also faced the challenge that the USMC, reduced in size following World War II, had to rebuild the 1st Marine Division, using elements of the 1st Provisional Marine Brigade fighting at Pusan as well as the 1st Marine Regiment and the 7th Marine Regiment, which pulled US Marines from as far away as the Mediterranean Sea to Korea for the task. MacArthur ordered Korean Augmentation To the United States Army (KATUSA) troops, ROK conscripts assigned to US Army units, to reinforce the 7th Infantry Division, while allocating all equipment coming into Korea to X Corps, despite it being crucially needed by the US Army's Eighth Army on the Pusan Perimeter.