A naval communications officer, he played key roles in signals intelligence during World War II in Washington, D.C., and on the staff of Admiral Chester W. Nimitz.

In February 1942, with the reorganization and centralization in Washington of U.S. Navy signals intelligence, he was put in charge of OP-20-G, the section of naval communications responsible for cryptanalysis.

[4] John Redman served as the Communications Officer on the staff of the Commander-in-Chief, United States Pacific Fleet, Admiral Chester Nimitz, from October 1942 to March 1945.

[5] His organisation's intentional withholding of intercepts and tips from the British, Indian and New Zealand allies and the US Army, who were also working on the decryption of other Japanese codebooks, was considered to have collectively held them all back.

Subsequently, he served as Director of Communications-Electronics for the Joint Chiefs of Staff in Washington, D.C. His final tour was as Commandant, Twelfth Naval District, from 1954 to 1957.