From December 1945, three months after the surrender of Japan, until November 1946 Adair served as GOC of the 13th Infantry Division, based in Greece during the Civil War, and receiving promotion to major general on 25 July 1946, with seniority from 12 November 1944. He finally retired from active service on 11 March 1947, but remained in the Regular Army Reserve of Officers until reaching the mandatory retirement age on 3 November 1957, his 60th birthday.