America's retreat and the global defence industry

The United States has long been the world’s pre-eminent armourer, supplying weapons on a scale unmatched by any other single power. For decades, her dominance in international defence sales was reinforced by a broad strategic architecture: alliances that required interoperability; overseas military commitments that signalled reliability; and a political consensus that the United States would stand with her partners in the face of danger. Yet the present period is marked by a perceptible drift towards geopolitical isolationism. This trend, which has moved from rhetorical flourish to operational fact, is already restructuring the global marketplace for military procurement. The dependence of other nations upon American arms, technologies and supply chains is showing signs of decline, as states quietly hedge against the risk that Washington may not remain a steadfast partner.

America’s isolationist impulse has multiple roots. Domestically, war-weariness after the conflicts in Iraq and Afghanistan fostered an electorate reluctant to support further military entanglements. The political polarisation of the last decade exacerbated this caution, introducing doubts about whether any administration could speak for the nation with predictable longevity. Congressional disputes over military aid packages have become ritualistic theatre, watched nervously by allies who require continuity rather than spectacle. Moreover successive Presidents have emphasised burden-sharing, reduced troop deployments and questioned the value of global commitments. Although none of these policies amounts to formal withdrawal, taken together they create the impression of a superpower reconsidering her role.

The effect upon foreign defence ministries has been swift. Nations that had long assumed access to American matériel now wonder whether such access will remain automatic in moments of crisis. The episodic delays in funding military assistance to Ukraine illustrated the fragility of reliance upon the US legislative process. European states, bemused that support for a war so central to their own security could become entangled in partisan disagreements thousands of miles away, have accelerated the development of indigenous defence industries. The European Union’s ambitious initiatives to expand production of artillery shells, air defence systems and armoured vehicles are emblematic of a broader determination to mitigate dependence on Washington. The result is a gradual diversification of procurement portfolios that previously would have leaned overwhelmingly towards American suppliers.

Meanwhile Asia’s security architecture is evolving in a similar direction. Although Japan, South Korea and Australia continue to purchase advanced US systems—including fighter aircraft, missile defence components and undersea technologies—they are concurrently investing in national production capabilities with unprecedented intensity. Japan’s defence industrial base is undergoing revitalisation after decades of relative quiescence; South Korea has emerged as a major arms exporter in her own right, offering competitive systems at lower cost and with fewer political strings. These developments are not mere adjuncts to American power; they are signs of self-reliance forged in an era of strategic uncertainty.

The Middle East, historically a region where American defence sales have been interwoven with political patronage, is not immune to this realignment. Gulf states, concerned that Washington may one day deprioritise the region or make arms sales contingent upon domestic political debates, have diversified their sources of supply. They now procure significant quantities of equipment from France, South Korea and even China, reducing Washington’s leverage. The dynamics of energy markets, and the perception that the United States is increasingly inward-looking, reinforce the desire for autonomy in defence procurement. Where once Washington’s approval was a near-monopoly gateway to advanced arms, it is now one option among several. Turkey is now buying her fighter jets from Britain.

China and Russia, although politically constrained in their export markets, have also benefited from this diversification. China’s growing presence in the unmanned systems market—drones, loitering munitions and surveillance aircraft—has secured customers in Africa, the Middle East and Latin America. Russia, despite the degradation of her defence industry due to the war in Ukraine, still maintains longstanding relationships with states that prefer suppliers unencumbered by Western conditionalities - in particular India. While these producers cannot displace the United States in qualitative terms, they contribute to a broader trend: global buyers no longer wish to be dependent upon a single supplier whose foreign policy direction is uncertain.

From the perspective of international order, this shift carries profound implications. For decades, American arms exports served not merely commercial interests but strategic ones; they embedded alliances, ensured interoperability, and allowed Washington to shape the military balance in numerous regions. As reliance upon US systems diminishes, so too does Washington’s capacity to influence conflict trajectories, mediate crises or deter aggression. A world with multiple competing defence suppliers is inherently more fragmented. Uniformity of standards erodes, logistical chains multiply, and political cohesion within alliances becomes harder to maintain.

For the United States herself, the economic consequences are significant but secondary to the political ones. Defence production remains a major industry, and global demand for advanced weapons systems is unlikely to evaporate. Nevertheless reduced reliance upon American equipment means reduced leverage. The political value of arms sales lies not only in revenue but in the strategic dependency they cultivate. If partners can rapidly shift to European, Asian or even domestic substitutes, Washington’s ability to translate matériel provision into diplomatic influence diminishes.

It would be misleading however to suggest that American isolationism has ushered in an immediate collapse of her defence export market. The United States still produces the most technologically sophisticated systems in the world, and many nations regard her as the only trustworthy supplier of certain categories of equipment. Moreover some of the diversification is precautionary rather than revolutionary; states hedge against the possibility of reduced American engagement but do not intend fully to sever procurement ties. Washington retains an unrivalled system of innovation, industrial depth and combat-tested capability. Yet reliance, unlike preference, is a matter of political calculation rather than sentiment. If allies no longer trust that the United States will be consistently available, they will behave as though she is not.

The long-term question is therefore whether America’s present isolationist mood represents a transient phase or a structural transformation in her foreign policy identity. Should Washington reassert her global leadership, rebuild bipartisan consensus on international engagements and recommit to alliance obligations, much of the perceived risk would dissipate. Procurement patterns, although slow to change, could re-align. But if isolationism hardens into a durable posture—where domestic politics routinely obstruct foreign commitments and global responsibilities are viewed as burdens rather than assets—then the world will continue to adapt by reducing reliance upon the United States.

In that scenario, America may find that her influence wanes not because she is overtaken by a rival superpower but because she voluntarily relinquishes the mechanisms that once bound other nations to her. Arms sales are one of those mechanisms. Their erosion would not only signal a shift in global defence markets; it would symbolise the retreat of a superpower that has chosen to become an island in a world that, more than ever, requires its stabilising presence.