Because of the large increase in the size of the air force, General Marshall suggested that Arnold select a few relatively junior air corps officers to be jumped in rank, thus preparing younger talent for effective leadership. Arnold replied that if he promoted these officers, he did not believe he could sustain the morale of the World War I flyers among the senior colonels. Many of these had been reduced from wartime rank in 1919 and had served as long as seventeen years as lieutenants. Jump-promoting "youngsters" in their thirties, he thought, would shatter the morale of the older, more experienced group. Marshall, therefore, proceeded on his own, immediately promoting Lt. Col. Laurence S. Kuter, age thirty-six, to the rank of brigadier general. Kuter had been a lieutenant colonel for only about three weeks when this promotion was made. Arnold was then instructed to place the thirty-six year old Kuter in a high position on his staff and be less concerned about the morale of the older officers and more concerned with providing incentives for the younger ones.