President Trump and the Future of NATO: A Shifting Alliance
President Donald Trump has long expressed skepticism about the North Atlantic Treaty Organization (NATO), viewing it as overly reliant on American resources. During his first term, he even floated the possibility of abandoning the alliance entirely. In his second term, Trump and his administration have made it clear that Europe’s security is no longer a top priority for the U.S., which aims to focus on its own borders and the Indo-Pacific region, where China has emerged as a major rival. Recently, Trump suggested that the U.S. might not defend NATO members who fail to meet their defense spending commitments, calling it “common sense.” But if the U.S. were to reduce or withdraw its support, what would Europe need to do to fill the enormous gap left by the American contribution? The answer, according to experts like former U.S. Ambassador to NATO Ivo Daalder, boils down to four key areas: money, personnel, time, and cooperation with Washington.
The Financial Challenge: Europe’s Spending Gap
Money is perhaps the most straightforward but most politically challenging aspect of Europe’s dilemma. The question is not just whether European nations can spend more on defense but whether they have the political will to do so, given the inevitable trade-offs and costs. Polish Prime Minister Donald Tusk highlighted the imbalance succinctly: “500 million Europeans ask 300 million Americans to protect them from 140 million Russians.” Tusk argued that Europe lacks the confidence to see itself as a global force capable of defending itself.
Friedrich Merz, who is likely to become Germany’s next chancellor, has proposed an ambitious plan to address this gap, suggesting Germany spend nearly $1.07 trillion on military and infrastructure over the next decade. Several countries, including Britain, Belgium, Poland, and Denmark, have also pledged to increase their defense budgets. This week, European Union leaders agreed to boost military spending, exempting it from normal debt limits. However, experts warn that these commitments still fall short of what is needed to replace the American contribution. A study by the Bruegel and Kiel Institute for the World Economy estimates that Europe would need to increase its annual defense spending by approximately €250 billion, or about 1.5% of the EU’s GDP, to match the current U.S. commitment. Currently, only five of NATO’s 32 members, including the U.S., spend more than 3% of their GDP on defense.
Europe’s military capabilities also lag behind in terms of advanced weaponry, particularly in integrated air and missile defense systems and long-range precision strike capabilities. Additionally, Europe lacks “strategic enablers,” such as transport aircraft, drones, and satellites, which are critical for intelligence, surveillance, and reconnaissance. While Europe has the capacity to produce more of its own weapons, better coordination among nations is needed to invest in the right industries and jointly purchase equipment. Europe also needs to replenish its stockpiles of ammunition and missiles, which have been depleted during the war in Ukraine.
The Personnel Problem: Building a Capable Workforce
Replacing the U.S. military presence in Europe is not just about money; it also requires a significant increase in personnel. Currently, there are about 100,000 U.S. troops stationed in Europe, a number that could fit into the University of Michigan’s football stadium, according to former U.S. Army Europe commander Ben Hodges. Even if European nations increase their military spending, it seems almost impossible for them to replace these troops quickly, let alone sustain independent operations for an extended period.
For instance, 20,000 U.S. troops were deployed to Europe after Russia invaded Ukraine in 2020 to bolster NATO’s deterrence capabilities. Analysts expect the Trump administration to withdraw these troops soon. Another 40,000 U.S. troops are rotated into Europe on expensive deployments, which Trump is also likely to curtail. Europe faces several challenges in replacing these forces. Only a handful of European countries still have conscription-based militaries, and attracting and retaining skilled personnel is difficult due to better pay and career prospects in the civilian sector. Even when soldiers are trained, retaining them—especially in high-tech fields like engineering and mechanics—is a struggle.
Compounding these challenges, NATO is pushing its members to meet the requirements of a new force model, which would require more than 300,000 troops to be deployable within 30 days to reinforce the alliance’s eastern flank in the event of a crisis. For now, there are simply not enough soldiers, logistics specialists, and intelligence officers to meet this demand. As Jim Townsend, a former U.S. deputy assistant secretary of defense, put it, “European armies are too small to handle even the arms they’ve got now.” While some European militaries, such as those of Britain and Denmark, are highly capable, they would struggle to sustain intense combat operations for more than a few weeks.
Time: The Long Road to Self-Reliance
Replacing the American contribution to NATO is a daunting task that cannot be accomplished overnight. Building the necessary military capabilities, purchasing or producing advanced equipment, and recruiting and training additional troops will take years, if not decades. In normal circumstances, it could take Europe at least a decade to catch up, according to Camille Grand, a former NATO assistant secretary general. While the urgency of the situation might accelerate some processes, critics argue that Europe has dragged its feet for far too long, ignoring clear signals from the U.S. since Trump’s first term.
American officials from both parties have been urging European allies to take greater responsibility for their own defense for decades. French President Emmanuel Macron’s warning in 2019 about the fading American commitment to NATO was largely ignored at the time. Europe is now scrambling to address these issues, but it cannot magically reduce the time needed to transition from American dominance of NATO without risking its security. Most importantly, this transition would require the U.S. to aid the process, synchronizing its withdrawals with Europe’s buildup.
The Need for U.S.-European Cooperation
Shifting from a U.S.-dominated defense framework to a European-led one would be perilous without close American cooperation. A sudden withdrawal of U.S. forces could embolden Russian President Vladimir Putin, who has long sought to weaken NATO. The U.S. must be willing to gradually withdraw its key capabilities only when Europe is ready to take over, according to Ivo Daalder. For example, even in Ukraine, where 900,000 Ukrainian soldiers are pinned down against the Russian army, a European commitment of 30,000 to 40,000 peacekeeping troops could strain NATO’s ability to deter Russia from testing the alliance elsewhere, such as in the Baltics.
Some experts suggest that a European force in Ukraine could operate under NATO’s command structure, utilizing existing NATO assets like surveillance planes and intelligence capabilities. Others, such as Max Bergmann of the Center for Strategic and International Studies, argue that it is time to revisit the concept of a unified European army, an idea long opposed by the U.S. A single European army could reduce duplication and improve efficiency, but questions about who would command it and under what political authority remain unresolved. A standing European army, Bergmann argues, need not replace the U.S. in every capacity but could be integrated into NATO to serve its primary purpose: deterring Russia from invading member states.
Conclusion: Europe’s Path to Self-Reliance
Europe’s ability to step into the shoes of the U.S. and take greater responsibility for its own defense is a monumental task, but not an impossible one. On paper, Europe has the resources: nearly 2 million personnel in uniform and a combined annual defense spending of roughly $338 billion. This is more than enough to deter Russia and establish Europe as a formidable military power. However, turning this potential into reality will require sustained political will, increased spending, better coordination, and time. Most critically, it will require cooperation with the U.S. to ensure a smooth transition and avoid creating security vacuums that Russia could exploit.
While Europe has made progress in recent years, the road to self-reliance is long and fraught with challenges. The U.S. must balance its desire to focus on other priorities with its enduring interest in a stable and secure Europe. For its part, Europe must summon the courage and unity to invest in its own defense and forge a stronger, more integrated military presence. The future of NATO and the security of Europe depend on it.
