This monograph is the fifteenth in a series of historical studies covering USAF plans, policies, and operations in Southeast Asia, published under the general title, The Air Force in Southeast Asia. Its focus is the role of the Air Force in support of American Decisions to withdraw U.S. combat troops and to turn the conduct of the war over to the South Vietnamese. Massive USAF efforts were devoted to attacking and destroying enemy stockpiles and troop concentrations in Cambodia and Laos, to supporting South Vietnamese ground attacks in the Laotian panhandle, to attempting to Vietnamize the interdiction function, and finally, to countering the enemy air buildup in late 1971. Complicating these endeavors was the requirement to withdraw certain American air units as part of the overall drawdown from Southeast Asia. In describing these actions, the author reviews key national policies and other developments that affected operations. These provide a background for understanding the dramatic events of 1971 in which the USAF was so much involved. It is an exciting and significant aspect of Air Force history.