Though retired from the military, Middleton was soon called to serve in a variety of advisory capacities. In April 1946 he was appointed to the Doolittle Board, set up to investigate officer-enlisted men relationships, and headed by former Air Corps General James H. Doolittle. The board made a number of recommendations, one of the more significant ones being to allow the non-commissioned officers to establish their own clubs, a recommendation supported by Bill Mauldin. Three years later Middleton was asked to serve on the Military Education Panel of the Service Academy Board to look at the curricula of the Military and Naval Academies, and the proposed Air Force Academy as well. Working for nine months on recommendations, Middleton stressed a more liberal education for the academies, and much of what he recommended was accepted.