The idea of renaming the US Department of Defense back to the “Department of War” is, in fact, a return to the original nomenclature rather than a brand-new invention. The United States originally maintained a War Department from the nation’s founding through World War II, led by a Secretary of War. In the aftermath of WWII, however, American leaders deliberately shifted away from the blunt War label. In 1947, President Harry Truman urged that US military power be seen as a force for peace, not for conquest, which was one reason the old War Department name was dropped.

Congress reorganized the military under the 1947 National Security Act, initially calling it the “National Military Establishment.” That unwieldy name (unintentionally abbreviated as “NME,” sounding like “enemy”) was quickly changed in 1949 to the more reassuring “Department of Defense.” This rebranding reflected the post-WWII ethos: America’s armed forces were to be guardians of peace and stability, part of a new international order aimed at preventing another global war. The shift from “War” to “Defense” signified an emphasis on deterrence and collective security, in line with the founding of the United Nations and NATO as institutions to uphold peace. Even during the ensuing Cold War, US leaders often spoke of “peace through strength,” maintaining massive military capabilities (including a nuclear arsenal) ostensibly to deter war rather than to wage it. In short, the post-1945 world saw defense and deterrence rhetorically prioritized over overt references to waging war.

The Post-Cold War “Security” Era

When the Cold War ended in 1991, the United States found itself without a peer competitor. This brief unipolar moment ushered in optimistic talk of a “liberal world order” and a broadened concept of global security. The triumph of liberal democracy was proclaimed, and some even argued we had reached the “end of history” – a future where major wars between great powers would no longer occur. Indeed, in the 1990s, international discourse shifted toward security in comprehensive terms: collective security arrangements, peacekeeping missions, and humanitarian interventions took center stage. US foreign policy focused on concepts like global security, human rights, and stability, often assuming that outright war between nations was a fading threat.

However, this optimism proved premature. The post-Cold War years did not bring an “eternal peace” – conflicts continued to erupt in various parts of the world, and nation-states remained guided by power and national interests despite the hopeful rhetoric. Lacking an obvious rival, the United States still found itself drawn into military interventions (e.g. the Gulf War, the Balkans), and it eventually identified new adversaries such as global terrorism to justify its security posture. In essence, during the unipolar era the lexicon emphasized security and peacekeeping, but the underlying reality of force in international relations never disappeared. The term “security” took the stage, as the world talked about cooperative security and a “peace dividend,” yet this was a veneer over persistent geopolitical tensions.

War Returns in a Changing Global Order

Today, the world’s geopolitical climate is darkening, and war is once again in the spotlight. Several decades after the Cold War, the international order is undergoing a profound transformation – often compared to the tumultuous era between World Wars. Power dynamics are shifting, eroding the brief post-Cold War illusion of unchallenged US dominance.

A multipolar or at least more contested world has emerged, bringing the prospect of great-power competition back into focus. The rise of new challengers and the resurgence of old rivalries mean that military conflict is no longer seen as unthinkable. For example, Russia’s recent actions on the world stage (such as the war in Ukraine) and other regional conflicts have shattered the notion that war was a relic of the 20th century. In Washington, strategic thinking has evolved to openly acknowledge near-peer competition and the possibility of major warfighting scenarios – a stark shift from the counterterrorism-centric outlook of the early 2000s.

As of September 5, 2025, this shift has been made explicit: President Donald Trump signed an executive order officially renaming the Department of Defense to the Department of War. This is no longer a symbolic proposal—it is now institutional fact. Advocates argue that the historical name “War Department” more bluntly conveys the military’s true mission and the hard reality of today’s threats. Such a change, floated for instance by President Donald Trump, is symbolic: it rejects the euphemism of “defense” and recognizes that preparing for war – not just deterring it – is now a priority.

Nonetheless, the very debate reveals how the spirit of global security has changed. The world is entering a more Hobbesian phase, echoing the earlier Cold War or even pre-WWII mindset when conflict among major powers was a central concern. Some observers have even begun referring to our era as a new “Thirty Years’ Crisis,” alluding to the unstable decades that led into World War II. No single power today can guarantee global peace and that the risk of a worldwide military conflict is now as serious as it was in the 1930s. In such an environment, talk of war – rather than broad “security” – has returned to the forefront of strategic discourse.

China’s Rise and Modern War Preparedness

A major driver of this shifting security paradigm is the rise of China. After decades of US hegemony, China’s rapid ascent as an economic and military powerhouse is fundamentally altering global power balances. This “return of China” to great-power status is often cited as the single most important factor in bringing war back into strategic calculations. Over the past two decades, China has dramatically expanded its military capabilities in parallel with its economic growth. Its defense spending surged from roughly $25 billion in 1994 to over $300 billion by 2024, making China the world’s second-highest military spender after the United States. These investments have translated into cutting-edge weapons programs and power projection capabilities that were unthinkable for China in the late 20th century. Beijing has launched an ambitious naval modernization – including building advanced warships and commissioning aircraft carriers. It now fields three aircraft carriers (two of them domestically built), with plans for at least four in the near future. In a historic move, China established its first overseas military base in Djibouti in 2017, signaling its intent to operate on a global scale. Each of these steps underlines China’s transformation from a regional power into a peer competitor capable of challenging US military primacy in key domains.

Beijing’s WWII Victory Day parade – only the second such grand military parade China has ever held to mark the end of World War II – exemplified this new normal. The 90-minute spectacle, attended by dozens of world leaders, was widely viewed as a showcase of China’s expanding military strength and a bid to cement its status as a global leader. In an opening address at the parade, President Xi Jinping struck a defiant tone: he lauded China as a “strong and self-reliant” nation that “fears no violence,” declaring that the country’s national rejuvenation is “unstoppable.”

The imagery and rhetoric from that event were telling – a clear message that China is not only remembering past wars but also preparing for potential future ones. Against this backdrop, Washington’s decision to officially restore the “Department of War” takes on even greater significance: it signals an acknowledgment that US–China relations are defined by open military rivalry rather than cooperative security. 

The rise of China has thus injected a new urgency into defense planning across Washington and allied capitals. The Pentagon, after decades of focusing on counterinsurgency and counterterrorism, is once again refocusing on high-intensity warfare, great power competition, and deterrence by force. The shift in language – from security cooperation back to war-fighting readiness – mirrors the reality of a more challenging strategic landscape shaped by China’s military ascent. In essence, China’s rise has brought the specter of inter-state war back to prominence, reinforcing the argument that the spirit of global security now is closer to that of the pre-1990 era, when military rivalry was at the core of international relations.

Toward a New Era of War and Security

While once a hypothetical, the renaming of the Department of Defense to the Department of War has now become reality. The symbolism matters: it acknowledges that the geopolitical climate has evolved from the comparatively benign hopes of the post-Cold War period to a far more adversarial and uncertain reality.

The old War Department moniker is not new – it harkens back to America’s earlier history – but reviving it today signals a profound change in mindset. It suggests that US policymakers see the coming years as fraught with the possibility of armed conflict, requiring a frank emphasis on war preparedness over the softer rhetoric of defense and security.

 

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