Why has Trump renamed the US Department of Defense to Department of War?

US President Donald Trump plans to sign an executive order on Friday to change the name of the Department of Defense to the Department of War, as part of his drive to project a strong image of America's military might.

Although the Republican president cannot formally change the name of the Department of Defence — America's defence ministry — without congressional approval, Trump is set to authorise the Pentagon to use “secondary titles" like “secretary of war” and “Department of War” in the meantime.

The order also directs US Defense Secretary Pete Hegseth to recommend potential legislative moves to rename the department permanently.

The plans were disclosed by a White House official — who requested anonymity ahead of the public announcement — and detailed in a White House fact sheet.

After Fox News revealed the plans for the executive order, the Pentagon chief took to social media and shared a post stating “Department of War”.

This rebrand has not come out of the blue, as Trump and Hegseth have repeatedly talked about changing the department’s name, with Hegseth even creating a social media poll on the topic in March.

Speaking to reporters in August, Trump stated, “everybody likes that we had an unbelievable history of victory when it was the Department of War. Then we changed it to the Department of Defence.”

When confronted with the possibility that making the name change would require an act of Congress, Trump told reporters that “we’re just going to do it.”

“I’m sure Congress will go along if we need that,” he added.

Previously known as Department of War

Although Trump’s executive order has sparked a political and legal controversy, the Department of Defense was actually first called the Department of War when it was created in 1789, the same year that the US Constitution took effect.

The department kept this name up until 1947, when right after World War II President Harry Truman signed the National Security Act, which merged the previously separate Army, Navy and Air Force.

In turn, Truman rebranded the ministry and named it the National Military Establishment.

Yet, the National Military Establishment would be a short-lived title, as two years later in 1949, the government arm was renamed and branded the Department of Defense.

A slew of changes backed by the Trump administration

The move is just the latest in a long line of cultural changes Hegseth has made to the Pentagon since taking office at the beginning of the year.

Early in his tenure, Hegseth pushed hard to eliminate what he saw as the impacts of “woke culture” on the military by not only ridding the department of diversity programs but also removing libraries and websites of material deemed to be divisive.

In turn, hundreds of books, which included titles on the Holocaust, were reviewed and removed from military academies.

Meanwhile, thousands of websites honouring contributions to the military from women and minority groups were also deleted.

“I think the president and the secretary have been very clear on this — that anybody that says in the Department of Defense that diversity is our strength is, is frankly, incorrect,” Pentagon spokesperson Sean Parnell told reporters in March when quizzed on these decisions.

Hegseth has also presided over the removal of all transgender troops from the military in line with an executive order signed by Trump in January. Transgender people have said the decision was both “dehumanising” and a show of “open cruelty”.