Following the War, he returned to his civilian job as journalist for "The New York Times", but retained his reserve commission. Adler was recalled for federal service in 1940 and reached the rank of Brigadier general. He later served as Assistant Division Commander, 6th Infantry Division during New Guinea campaign, but reverted to the inactive status in late 1944. However Adler remained active in the Army Organized Reserve and reached the rank of major general and commander of 77th Infantry Division.