As a lieutenant general, Walker served as the deputy commanding general, United States Army Forces Command at Fort McPherson, Georgia from 1975 to 1977. In 1977 he was selected for promotion to general, at the time the youngest four-star general in the army, and appointed to his final position as commanding general, Allied Land Forces Southeast, headquartered in Turkey. His time in Turkey was a tumultuous one, coinciding with the United States arms embargo against Turkey for deploying troops to Cyprus in 1974. A Turkish general was assigned command of Allied Forces in Turkey as a way to maintain positive relations with Turkey; with no four-star positions available, the army offered Walker assignment as chief of staff for the United States European Command, a three-star position. Walker declined this post, and opted to retire. At the end of his assignment in Turkey, he was awarded the Defense Distinguished Service Medal and the Turkish Armed Forces Medal of Distinguished Service.