Trump Renames Department of Defense to Department of War

President Donald Trump signed an executive order Friday afternoon to rename the Defense Department to the Department of War.

“It’s an honor to sign this. I think that’s a big one, I’ll be honest,” Trump told reporters in the Oval Office.

The president was joined at the White House by Defense Secretary Pete Hegseth and Air Force Gen. Dan Caine, the chairman of the Joint Chiefs of Staff, for the announcement. Trump said the three men talked about the name change for months.

It was unclear if the president can unilaterally rename the department without legislation from Congress. In the meantime, Trump authorized the Pentagon to use secondary titles such as “secretary of war” and “Department of War” in official correspondence and public communications so the department can go by its original name.

Trump has been asked before about making the name change and requiring an act of Congress.

“I’m not sure they have to. We’re going with it, and we’re going with it very strongly,” the president said when asked again Friday. “We’ll put it before Congress.”

Three Republican lawmakers – Rep. Greg Steube of Florida and Sens. Mike Lee of Utah and Rick Scott of Florida – introduced legislation this week to redesignate the Defense Department as the Department of War and rename the position of Defense Secretary to Secretary of War.

“For the first 150 years of our military’s history, Americans defeated their enemies and protected their country under the War Department,” Lee said in a statement. “I’m proud to introduce the Department of War Restoration Act to make President Trump’s return to tradition permanent in federal law. It should always be clear to anyone who would harm our people: Americans don’t just play defense.”

Shortly after reports surfaced Thursday that Trump would sign the executive order, Scott called on his colleagues in a post on X to pass the “bill to make this change the law of the land.”

The administration has teased the change for a while. Last month in the Oval Office, Trump told reporters that “everybody likes that we had an unbelievable history of victory when it was Department of War. Then we changed it to Department of Defense.” Defense Secretary Pete Hegseth even created a social media poll on the topic in March.

Trump asked Hegseth to say a few words at the White House and referred to him as the “Secretary of War,” which drew some laughs in the room.

“It’s restoring, as you’ve guided us to Mr. President, restoring the warrior ethos,” Hegseth said. “We’re going to go on offense, not just on defense. Maximum lethality, not tepid legality. Violent effect, not politically correct. We’re going to raise up.”

President George Washington created the War Department in 1789. It oversaw the Army, while the Navy and Marine Corps were overseen by a separate Department of the Navy starting in 1798. This structure remained until 1947, when President Harry Truman received Congress’ approval to create a National Military Establishment to oversee the Army, Navy and the newly formed Air Force. The National Security Act of 1947 also established the Joint Chiefs of Staff as an organization to advise the president on military planning and strategy.

In 1949, the National Military Establishment became today’s Department of Defense.

When Truman signed the act into law, he believed it would “permit us to make real progress toward building a balanced and effective national defense.”

There were several reasons for why the Pentagon became the Defense Department, said Charles Bowery, the executive director of the U.S. Army Center of Military History. The U.S. was growing as a world power in the 1940s. The president at the time, who was commander in chief, was “really unable” to exercise the duties of commander in chief, along with all of his other duties as the elected leader.

After World War II, the demobilization of U.S. forces created some concern. By the end of the war, the U.S. had about 12 million people under arms. Demobilization took place from 1945 to 1947 and the U.S. had about one twelfth the force it had in the early days of the Cold War, Bowery said.

“The military is like, ‘Wait a minute. The nation is trying to demobilize and put millions of people back into civilian life. And then all of a sudden, oh, no, hold on. Now we have to ramp back up again,’” Bowery said.

It was determined that a national institution was needed to account for the complexity of national defense in the atomic age.

“The spirit and the intent behind a defense establishment, a national security establishment, is that the nation’s security and the nation’s defense are about a universe of things. Lethality is just one of those things,” Bowery said. “It’s easy to criticize this decision of creating a Department of Defense as well. What I see in the history of this was, was a very thoughtful attempt to deal with problems that they saw in the past – in World War II, in the Cold War, in the current environment – and to create a structure that would best account for them and to keep the United States safe.”

The Pentagon quickly started working to show off the War Department name. The name on the X account became the “Department of War.” The first post in all caps said, “We are the War Department,” followed by a video highlighting the department’s mission.

The name plate on Hegseth’s office door was changed to reflect his new title of Secretary of War.

The effort to rename the Defense Department follows a number of similar steps by Hegseth to change the names of bases and ships. When Trump returned to office, the administration reversed a Biden-era decision that had removed Confederate-era names of bases by restoring the old names by identifying service members with last names similar to those of the Confederate honorees.

It cost more than $60 million to rename bases at the time. Trump said “we’re not going to be spending very much money” to become the War Department. A department official, who spoke on the condition of anonymity, said the Pentagon will have a “clearer estimate to report at a later time.”

In June, Hegseth also ordered the renaming of an oiler ship named after gay rights activist and Navy veteran Harvey Milk.

The last renaming of a major military command also occurred under Trump, when then-Defense Secretary Jim Mattis announced in 2018 that U.S. Pacific Command would be renamed U.S. Indo-Pacific Command, to better reflect the importance of India’s role in U.S. defense strategy in the East.