The Department of War Makes America Look Weak

With the stroke of a pen, President Trump has ordered the Pentagon to be renamed the Department of War. It is a dramatic gesture, but one that leaves the US looking smaller, not stronger. He defended the change by noting America ‘won World War I and World War II’ under the old name and insisting that ‘we want offense too.’ But that outlook is precisely what alarms allies and emboldens adversaries: it signals that Washington defines itself by fighting wars, not by preventing them.

The Department of War was a narrow institution, abolished more than seventy-five years ago because it was inadequate for America’s global responsibilities. Rebranding the Department of Defense under that name again does nothing to upgrade US capabilities, strengthen alliances, or dissuade adversaries. It is symbolism masquerading as strategy. At a time when America faces real defence challenges – from modernising its nuclear arsenal to deterring Russia and China – choosing to rename the Pentagon is a distraction that confuses rhetoric with readiness.

The War Department, created in 1789, was a limited institution. It oversaw only the Army (including what were then the Army Air Forces). The Navy had its own cabinet-level department, the Marine Corps was subordinate to that, and the Air Force as an independent service did not yet exist. What Americans call ‘the Pentagon’ today – the massive complex completed in 1943 – was built to house the War Department. But the building outlived the institution it was meant to house.

In the aftermath of the Second World War, US leaders recognised that this structure was inadequate. Modern war demanded unified command across land, sea, and air, as well as permanent readiness in an age of nuclear weapons. The National Security Act of 1947 created a Secretary of Defense to coordinate the services, and in 1949 Congress renamed the institution the Department of Defense.

This was not cosmetic. The leaders who backed that change – George Marshall, Dwight Eisenhower and James Forrestal – had guided America through the largest conflict the world had ever seen. They did not speak of war lightly. Their decision reflected hard-won lessons: that American power must be organised for more than episodic conflict, and that military strength had to be integrated into a broader strategy of deterrence and alliance.

Words mattered. ‘War’ implied a reactive office, mobilised intermittently when fighting began. ‘Defense’ captured the reality of America’s new role: a permanent guarantor of security.

Words still matter today. US allies avoid ‘war’ labels, with Britain’s Ministry of Defence, France’s Ministry of the Armed Forces, Canada’s Department of National Defence, and Australia’s Department of Defence. America’s adversaries do the same, from China’s Ministry of National Defense and Russia’s Ministry of Defense to North Korea’s Ministry of National Defense and Iran’s Ministry of Defense and Armed Forces Logistics.

These choices are far from cosmetic: they shape perceptions of credibility, reassurance, and deterrence, especially for allies who depend on US guarantees. Across both democratic and authoritarian systems, states recognise the importance of presenting their armed forces as instruments of protection rather than engines of conquest. Indeed, since 1945 the UN Charter has formally abolished war as a legitimate instrument of statecraft. For Washington to move in the opposite direction would not project strength but weakness – an unhelpful signal in a dangerous world.

That is why the choice in 1949 carried political weight. Domestically, Americans were wary of a permanent ‘war’ department. Internationally, the US was presenting itself as a stabilising force, building NATO and supporting the UN Charter. Casting the Pentagon as orientated toward ‘defense’ was essential for both credibility and reassurance.

Undoing that choice now has immediate consequences. Some allies will interpret the change as America turning away from collective defence toward unilateral combat, while others will question Washington’s seriousness and judgment in addressing the real security challenges they face together. Rivals will read it as confirmation of aggressive intent. It even hands America’s adversaries an easy propaganda win, allowing them to portray Washington as aggressive rather than protective. That step would be especially damaging at a time when China is orchestrating lavish parades to cast itself as the confident alternative pole in world affairs. At home, the Pentagon will waste months on signage and symbolism at a cost of up to $1billion when it should be focused on substance. Nor is the change likely to endure; Congress enshrined the Department of Defense in law in 1949, and an executive order cannot erase that statute.

The Department of War belongs to the past. Congress created the Department of Defense in 1949 for good reason: to unify the services, deter conflict, and reassure allies of America’s defensive purpose. An executive order cannot erase that history or substitute theatre for strategy. Restoring that name would not only reaffirm America’s defensive commitments but also demonstrate to allies and adversaries alike that Washington remains committed to responsible global leadership. Lawmakers should move quickly to reassert the statute and restore the Department of Defense: a name that reflects America’s enduring role as a defender, and the hard-earned lessons of the generation that built the postwar order.

© RUSI, 2025.

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