Since the end of the Second World War, the US has served as the principal architect and guarantor of Western Europe’s security, primarily through its leadership of the North Atlantic Treaty Organisation (Nato) and its close partnership with the European Union (EU). These institutions have supported transatlantic stability, deterred threats and promoted peace and prosperity in Europe.
However, recent shifts in the global balance of power, evolving security challenges and ongoing debates about equitable burden-sharing have prompted renewed scrutiny of the durability and future trajectory of these alliances. This discussion is influenced by multiple factors, including intensifying geopolitical competition with China, the ‘America First’ doctrine, and the renewed military presence of Russia along Europe’s eastern borders.
From a neorealist perspective, this dependence is a rational response to the anarchic international system, where states seek alliances to balance against threats and augment their power. The US’s military strength, global reach and willingness to deter adversaries like Russia make it an indispensable partner for European security.
Opportunities from a US pullback
While the prospect of a US pullback raises understandable anxiety, it also presents significant opportunities for Western Europe to strengthen its unity and capabilities. A reduced US role could catalyse the development of a more independent European defence and foreign policy. Strategic autonomy means the ability of European countries to set their priorities and collaborate on security without over-reliance on the US.
This would encourage increased defence spending, enhanced readiness, and the development of joint operational capabilities. EU-led defence initiatives such as Permanent Structured Cooperation (PESCO) and the European Defence Fund (EDF) could gain momentum, driving the creation of integrated European military units and standardising procurement processes. The result would be a more capable and autonomous European pillar within Nato and the EU, better equipped to act independently when necessary.
Historically, European defence industries have lagged behind the US in investment and innovation. A US pullback would incentivise European nations to invest more heavily in their defence industrial base, fostering technological innovation, economic growth and job creation. Cross-border collaboration among European defence firms could lead to the emergence of pan-European champions capable of competing globally, while also building more resilient supply chains.
The shared challenge of adapting to a reduced American role could act as a driver for deeper political integration and a stronger European identity. External threats have historically served as catalysts for cooperation among European nations. The need to fill the security vacuum left by the US could encourage EU member states to overcome longstanding divisions and work more closely together in defence, foreign policy and crisis management.
However, while these opportunities are significant, they are accompanied by a range of challenges and risks that must be addressed if Western Europe is to navigate a future with diminished US involvement successfully.
Challenges and risks
The US maintains a network of strategically located bases, advanced intelligence, surveillance and reconnaissance (ISR), missile defence and command infrastructure across Europe. The loss of these capabilities would leave Europe with immediate and profound gaps in strategic airlift, logistics, refuelling, missile defence and cyber operations. European militaries currently lack the scale, flexibility, and technological depth provided by the US, and achieving self-reliance would require years of investment and political commitment.
Chronic underinvestment in defence is a persistent problem. Most Western European countries have failed to meet Nato’s target of spending at least two per cent of GDP on defence. Public expectations of a “peace dividend” have made it politically difficult to raise military budgets, especially when weighed against domestic priorities like healthcare and education. Reliance on the US security umbrella has enabled many states to “free ride” on American commitments.
The visible presence of US forces and the credibility of American security guarantees have been central to deterrence in Europe. A US pullback could be perceived as a weakening of deterrence, potentially emboldening adversaries to test Europe’s resolve through hybrid warfare, cyberattacks, or direct military provocations. The loss of the US nuclear umbrella would also leave many European countries exposed to coercion, raising difficult questions about whether to develop new nuclear capabilities or seek alternative arrangements.
Divergent threat perceptions and burden-sharing disputes have long complicated collective defence efforts. Countries on Nato’s eastern flank prioritise deterrence against Russia, while southern states focus on instability in North Africa and migration. Without the unifying influence of US leadership, these differences could become more pronounced, undermining consensus and solidarity.
These challenges are further complicated by ongoing conflicts and strategic uncertainties, such as the Russia-Ukraine war, which continues to test the resilience and unity of the Nato alliance. The war has exposed Western Europe’s ongoing reliance on the US for security, as the EU’s limited military capabilities and strategic autonomy remain evident in high-intensity conflicts.
The US remains the backbone of Nato’s defence, providing vital technology, intelligence and a nuclear umbrella. While the war has united allies in supporting Ukraine and prompted increased European defence spending, it has also strained Nato due to US delays and internal debates. Although a complete US withdrawal from Nato is unlikely, given its strategic importance, the possibility of reduced engagement underscores the need for Europe to strengthen its security and contingency planning.
Way forward
As Western Europe contemplates a future with potentially less American involvement, it must consider concrete steps to bolster its own defence and strategic autonomy. This includes increasing defence spending, accelerating military modernisation and deepening cooperation within the EU framework.
Initiatives like PESCO and the EDF should be expanded to promote interoperability and joint procurement, while major collaborative projects such as the Future Combat Air System (FCAS) and the Main Ground Combat System (MGCS) are essential for advancing indigenous capabilities. The effectiveness of these measures will depend on the political will of European leaders to overcome national differences and commit to a cohesive security strategy.
While the risks associated with diminished US involvement are considerable, they may also present an opportunity for Western Europe to strengthen its security posture and assume a more autonomous role in the international system. Ultimately, the choices made in response to these challenges will determine whether Europe can transform adversity into opportunity and secure its future in an uncertain world.
While the likelihood of a US withdrawal from Nato remains limited in the immediate term due to the alliance’s centrality to American strategic interests and global stability, such a development cannot be entirely discounted amid evolving geopolitical dynamics.
A US pullback would expose Western Europe to significant risks and uncertainties, given its longstanding reliance on American military capabilities and leadership. Nevertheless, neorealist theory suggests that systemic shifts of this nature can prompt adaptation and innovation, compelling European states to enhance their defence capacities, accelerate integration and pursue greater strategic autonomy.
Looking ahead, European policymakers must seize the initiative by investing in defence, fostering unity and articulating a coherent strategic vision to ensure that Western Europe remains secure and resilient in the face of changing global realities. The decisions made at this pivotal juncture will not only shape the future of European security but also influence the broader contours of global order in the decades to come.
First Admiral Ts Gs Lukman Hanafiah Azamar Omar is with the Royal Malaysian Navy and currently attending the National Resilience College, PUSPAHANAS.
The views expressed here are the personal opinion of the writer and do not necessarily represent that of Twentytwo13.
