On Friday, September 5, 2025, Trump signed Executive Order 14347, “Restoring the United States Department of War,” making “Department of War” a “secondary title” for the Department of Defense and letting officials substitute “war” into their titles, so that Defense Secretary Pete Hegseth could call himself Secretary of War. Trump said the name “sends a message of victory.”
Only Congress can change a department's legal name. Congress established the Department of Defense name in 1949, the culmination of President Harry Truman's effort to unify the Army, Navy and Air Force under one department. Constitutional scholar Steve Vladeck told NPR that the “legal name can't change without Congress.” Trump said the administration would ask Congress to codify the change but added, “I'm not sure they have to.”
The department now calls itself the Department of War on its War.gov website and in many official communications, and in November 2025 the name was set in bronze at Pentagon entrances. In January 2026 the Congressional Budget Office estimated the rebranding would cost $10 million to $125 million depending on how broadly and quickly it is applied, and that a statutory renaming “could cost hundreds of millions of dollars.”
Correction (October 14, 2026): This entry previously dated the order to September 4, 2025; the Federal Register records its signing on September 5, 2025. It also said the War Department dated to 1789 and that Truman renamed it to move away from militarism, and that critics called the move authoritarian; we could not source those claims and removed them. Before 1949 the War Department oversaw the Army, while the Navy had its own department, and the summary no longer describes the War Department as overseeing the whole military.