During the Cuban Missile Crisis, Unger served as operations director of the Joint Chiefs of Staff.

From November 1966 to January 1968 Unger served as High Commissioner of the United States Civil Administration of the Ryukyu Islands.

During this time he became the first High Commissioner to begin the process of granting more power to the people of the Ryukyu Islands.

This resulted, in 1968, in the election of Chobyo Yara, a reform candidate who served until 1972 when control of Okinawa was given back to Japan.

[1] After leaving Okinawa Unger served as plans and policy director for the Joint Chiefs of Staff until his retirement in 1970.