President Trump Wants to Rename the Department of Defense, but Is That Legal?
Trump's Executive Order gives the department a secondary name.
Published Sept. 5 2025, 10:39 a.m. ET

Although he's less than a year into his second term in office, President Trump has already done plenty of things that have left us wondering whether he is pushing the bounds of what the president's role is supposed to be. In early September, he announced that he would be renaming the Department of Defense the Department of War, which was its name for much of its history.
Following the news that he wanted to rename the department, many naturally wondered whether that's something that's within the president's power. Here's what we know about whether he can do that.

Can Trump rename the Department of Defense?
Trump cannot unilaterally rename the Department of Defense. Although it's part of the executive branch, it was created and named by Congress, and changing its name would similarly require an act of Congress. Instead of renaming it, then, Trump is planning to sign an Executive Order that will allow Defense Secretary Pete Hegseth to use secondary titles like “secretary of war” and “Department of War” in official correspondence and public communications, as well as during formal ceremonies.
The order will also require that all other parts of government “recognize and accommodate these secondary titles in internal and external communications.”
Basically, then, it seems like this Executive Order is giving the Department of Defense an official nickname of sorts that they will begin to use. It's a circumvention of Congress, but Trump is not actually changing the department's official name.
According to NBC, Trump made the name change after musing in August that the Department of War "had a stronger sound" and an "unbelievable history of victory."
"I don’t want to be defense only. We want defense, but we want offense, too," he added. "As Department of War, we won everything."
Hegseth has also been vocally supportive of a name change, saying that it would encourage a "warrior ethos" inside the department.
Congress first established a Department of War all the way back in 1789, but it was renamed the Department of Defense in the aftermath of World War II as part of a broader effort to consolidate all of the country's armed forces into a single department. The move back to the Department of War appears to be entirely symbolic for Trump and won't come with any corresponding reorganization of the department.
Trump has, throughout his time in office, appeared to be torn between wanting to be seen as a peacekeeper and to assert an American image of strength and valor. This renaming of the Department of Defense falls firmly into that latter category, and Trump has always been careful about branding things both personally and in office.
While the name change is not permanent yet, reports also suggest that Trump wants Hegseth to pursue a more permanent name change. That would require passage through both houses of Congress, which is certainly more difficult than just signing an Executive Order creating a secondary name, but also more permanent.