At the time of the
United States entry into the World War II, DeCarre still served with the Marine barracks at
Puget Sound. He remained in this capacity until end of July 1942, when he was transferred to the
2nd Marine Division in
San Diego and appointed its assistant division commander. For his new duties, he was also promoted to the rank of
brigadier general on August 19, 1942. The 2nd Division was sent to the
Pacific Theater in December 1942 under the command of Major General
John Marston. The 2nd Division subsequently participated in the Guadalcanal Campaign; however, Marston remained in New Zealand, because he was superior in time in rank to Army Major General
Alexander M. Patch, who was in charge of the entire offensive. This step has been made for the sweetening of the relationships between Marine Corps and Army. Nonetheless, DeCarre was in charge of all Marine ground units on Guadalcanal after the departure of the
1st Marine Division in October. General DeCarre remained temporarily in command of the 2nd Marine Division until May 1943, when he was relieved by Major General
Julian C. Smith. In the capacity of assistant division commander, he was succeeded by Brigadier General
Leo D. Hermle. DeCarre then returned to the United States in June 1943 and was admitted to the
Naval Hospital in San Diego for treatment of tropical disease. For his service on
Guadalcanal, DeCarre later received a Letter of Commendation for his outstanding work during the campaign from General Patch. After his recovery, DeCarre was assigned to
Camp Pendleton, where he was appointed chief of staff to Major General
Joseph C. Fegan Sr., commander of the base. DeCarre was later transferred to the
Marine Corps Base Quantico in April 1944 and served there for the rest of the War. He retired from the Marine Corps in June 1946 and was advanced to the rank of major general on the retired list for having been specially commended in combat. ==Decorations==