By Fatou Bojang (International Relations Students)

Overview

Donald J. Trump signed an executive order on September 5, 2025, titled "Restoring the United States Department of War." This order permits the Department of Defence to use the title "Secretary of War," the Department of War to use the title "Department of War," and so on in ceremonial documents, non-statutory materials, and public communications. In order to make the change permanent, the directive instructs the Secretary to suggest the necessary executive and legislative actions.

The fundamental questions of U.S. military identity, alliances, international signalling, and the larger global security architecture are all touched upon by this structural-symbolic transformation. On one level, it can seem like simple semantics, but on another, it might represent or trigger more profound postural adjustments. In the end, the question is whether this rebranding (and what it means) compromises global security. Strategic posture, alliance perceptions, enemy calculations, international conventions, and the risk of escalation are some of the interrelated aspects that determine the answer.

Historical Context
To understand the significance, it helps to trace the institutional evolution. The original United States Department of War was established in 1789 and existed until the post-World War II restructuring.  After the war, the National Security Act of 1947 and its amendment in 1949 reorganised U.S. military command, unifying the Army, Navy and newly created Air Force under a civilian Secretary of Defense, forming the DoD as it exists today. The renaming to “Defense” rather than “War” was symbolic of a new era of deterrence, collective defence, and avoiding large-scale war in the nuclear age.

By reversing that naming convention, the Administration signals a change in emphasis. In one official statement the White House fact sheet argued that the name “Department of War” ‘conveys a stronger message of readiness and resolve compared to “Department of Defense”, which emphasises only defensive capabilities’.

Implications for U.S. Strategic Posture
A name change of this kind is far more than cosmetic. It embeds a shift in posture: from defence to warfighting, from deterrence/minimisation of conflict to readiness for high-intensity combat. The rhetoric accompanying the change reinforces this: the Secretary of War proclaimed the new department “is going to fight decisively… we’re going to go on offense, not just on defense.

Such a posture has several consequences. First, it may signal to allies that the U.S. is less committed to purely defensive arrangements, and more willing to project force proactively. This can lead allies to question whether they are being drawn into a more aggressive U.S. policy. Second, adversaries may interpret the change as a destabilising signal: the institutional change suggests the U.S. is ready for war, rather than just deterrence. As one commentary puts it, “it signals that Washington defines itself by fighting wars, not by preventing them.

Third, the shift might influence resource allocation, doctrine, procurement and planning: an organisation that defines itself as a “War Department” may prioritise high-end warfighting capabilities (offensive cyber/space/air/sea/strike assets) at the expense of defence/refuge preparedness, deterrence diplomacy, and stability operations. That could reduce flexibility in peacetime, increase risk of miscalculation, and push the U.S. into more kinetic engagements.

Impact on Alliances and International Norms
The U.S. alliance architecture (e.g., NATO, bilateral defence treaties in Asia) built on the premise of collective defence and deterrence. Allies expect the U.S. to emphasise stability, forward presence, reassurance, and defence of the status quo. A renaming to “War Department” could undermine that reassurance by emphasising conflict readiness over collective security and defence of existing norms.

Allies might fear that U.S. policy will shift toward forcing outcomes rather than maintaining deterrence, and that their own security burdens may change. For example, less emphasis on diplomacy and more on combat means allies could be asked to participate in more aggressive operations or follow riskier missions. This may lead to reluctance among allies, fragmentation of coalitions, or a re-balancing of regional security relationships (e.g., in Asia, Europe).

Internationally, the name change also reverberates with norms about when use of force is legitimate. The current global security architecture emphasises defence, deterrence, collective security and the minimisation of armed conflicts. By returning to the label “War Department,” the U.S. distances itself rhetorically—and therefore perhaps operationally—from the defence / deterrence paradigm. This may embolden others who argue that war-fighting is normal, reducing the barrier to conflict escalation and weakening normative constraints on the use of force.

Risks of Disruption and Escalation
One major risk is signalling. If an adversary interprets the change as the U.S. moving toward “first-strike” or war-winning operations, they may respond by accelerating their own offensive capabilities, taking more aggressive posture, or undermining arms control. For instance, say a peer-competitor perceives the U.S. as orienting to war-fighting rather than just deterrence; that competitor might feel pressure to adopt a launch-on-warning posture, increase its nuclear or missile forces, or adopt more dangerous escalation dynamics.

Another risk is miscalculation. In crises, if the U.S. posture is more aggressive and less defensive, adversaries may feel they must act pre-emptively rather than wait for a deterrent to work. This could increase the likelihood of conflict. Similarly, allies might mis-judge U.S. intentions (assuming more aggressive operations) and either try to restrain the U.S.—creating friction—or be caught unprepared for a shift in mission.

A further risk is that internal U.S. policy focus might shift away from diplomacy, conflict prevention and multilateral engagement toward "winning wars" as the central mission. That could reduce investment in non-military tools (diplomacy, development, intelligence, multilateral institutions) that underpin global security. Without those, the stability-maintaining elements of the international system weaken and the possibility of local conflicts escalating to bigger wars grows.

Potential Mitigations and Counter-Considerations
 It is important, however, to recognise that while symbolism is powerful, concrete capabilities, doctrine, strategy and alliances determine outcomes more than a name. The U.S. retains an enormous defence establishment and is unlikely to abandon deterrence or alliances overnight. So the impact may be more gradual and mediated by broader policy decisions.

Moreover, the rebranding may serve domestic and ideological goals rather than a radical shift in policy. It could be argued to reflect continuity (the U.S. always wages wars) rather than a new doctrine. Some analysts describe it as “symbolism masquerading as strategy.”

Also, if the U.S. clearly communicates that the mission remains collective defence and deterrence but with a sharper edge, allies may be reassured rather than alarmed—especially if accompanied by reinvigoration of commitments (troops in Europe/Asia, missile defence, training). The name alone does not automatically change the substance if policy remains consistent.

Conclusion
The renaming of the Department of Defense to the Department of War is more than a matter of semantics; it signals a shift in U.S. military posture and identity toward war-fighting readiness rather than purely defensive operations. That shift has meaningful implications for international security: alliances might be unsettled, adversaries emboldened, escalation risks increased, and global norms weakened. In this sense, it can disrupt international security—not necessarily through immediate conflict, but by altering the strategic environment, signalling behaviour, and re-ordering expectations about how the U.S. uses force.

However, whether it leads to actual large-scale disruption depends on how the U.S. implements doctrine, communicates with allies, sustains its alliances, and maintains balance between offence and defence, diplomacy and deterrence. If the name change remains largely symbolic while policy stays steady, the international disruption could be limited. But if the name change foreshadows and guides a substantive strategic reorientation, the impact could be significant.

In sum, the re-branding of the U.S. defence establishment is a meaningful marker of intent. Its consequences for international security are real, and they merit cautious attention—not just for what the U.S. does, but how others respond.