Trump's NATO ultimatum: Will Europe rearm, fragment, or go nuclear?
American pressure has pushed European defense spending to record highs. But rising budgets mask deeper fractures over strategy, capability, and nuclear deterrence that could reshape transatlantic security for decades.
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The Phantom Limb
Europeâs security architecture feels pain from an appendage it no longer possesses. For seven decades, the continent outsourced its defense to Washington, and nowâas Donald Trumpâs second administration makes explicit what his first merely impliedâEuropean leaders confront a neural map of sovereignty that no longer matches reality. The brain insists the limb exists. The mirror shows otherwise.
Trumpâs burden-shifting strategy has achieved what decades of American diplomatic pressure could not: European defense spending is rising. Twenty-three of NATOâs thirty-two members now meet or exceed the 2% of GDP target, up from eleven just two years ago. European Union defense expenditure climbed from âŹ343 billion in 2024 to âŹ381 billion in 2025. Germany has committed âŹ100 billion in special defense funding. Poland spends 4% of GDP on its military.
Yet these numbers obscure a more troubling dynamic. The question is not whether Europe rearmsâit will. The question is whether rearmament produces genuine strategic autonomy or merely a more expensive form of dependence. Whether it strengthens NATO or fragments it. Whether it contains nuclear proliferation or accelerates it.
The answer, emerging from the fog of transatlantic recrimination, is: all of these, simultaneously.
The Transactional Turn
Trumpâs approach to alliance management represents not evolution but rupture. Traditional burden-sharing debates operated within a framework of shared values and mutual obligation. Trumpâs burden-shifting operates within a framework of bilateral transactions and conditional commitments.
The distinction matters. Burden-sharing assumes the alliance is a public good worth preserving; the debate concerns fair distribution of costs. Burden-shifting treats the alliance as a service contract subject to renegotiation or termination. When Trump publicly questioned whether he would defend allies who hadnât paid their dues, he wasnât negotiating termsâhe was revealing a fundamentally different conception of what NATO is.
According to analysis from the Small Wars Journal, Trumpâs strategy involves âdemanding that allies meet or exceed the 2% of GDP defense spending guideline to reduce disproportionate U.S. contributionsâ while using âthe threat of reducing American support to force compliance.â This is not subtle. It is not meant to be.
The psychological impact has been profound. A senior German official, asked in February 2025 whether Trump would defend European allies, responded with devastating clarity: âWe have to assume not.â The uncertainty, he explained, âis just too high.â This represents a collapse of the foundational assumption underlying European security since 1949: that American commitment could be relied upon.
European responses have diverged along predictable fault lines. Poland and the Baltic states, facing the most immediate Russian threat, have increased spending dramatically while simultaneously seeking bilateral security guarantees from Washington. France has accelerated rhetoric about European strategic autonomy while quietly acknowledging that its nuclear arsenal cannot credibly extend to protect Eastern Europe. Germany has announced historic defense investments while its coalition government struggles to define what those investments should buy.
The result is not coordinated rearmament but competitive positioning. Each European state optimizes for its own threat perception and domestic political constraints, producing aggregate spending increases without aggregate capability increases.
The Capability Gap
Money is necessary but not sufficient. Europeâs defense industrial base has atrophied over three decades of peace dividends. Factories that once produced artillery shells now make consumer goods. Engineers who once designed weapons systems now work in automotive or aerospace. The human capital and industrial capacity required for sustained military production cannot be rebuilt by budget appropriations alone.
Consider ammunition. Ukraine fires approximately 6,000 artillery shells daily. Russia fires 20,000. Pre-conflict, the United States produced 240,000 shells annuallyâbarely forty days of Ukrainian consumption. European production was proportionally lower. The gap between spending commitments and production capacity represents years, not months, of industrial mobilization.
This creates a paradox. European rearmament, to be rapid enough to matter strategically, must rely on American equipment and American production capacity. The more Europe rearms quickly to reassure Washington, the more it locks in dependence on US-origin systems, standards, and command architectures. Research on European defence industrial policy shows how NATOâs concept development approach has driven âisomorphic spilloverâ into European defense procurementâinstitutional convergence that deepens rather than reduces American influence.
The numbers tell the story. European F-35 purchases integrate European air forces into American supply chains, maintenance networks, and software update cycles. European purchases of HIMARS and Patriot systems create dependencies that will persist for decades. Even ostensibly European programs like the Future Combat Air System (FCAS) and Main Ground Combat System (MGCS) face delays and disputes that push procurement decisions toward off-the-shelf American alternatives.
Strategic autonomy, in this context, becomes a slogan rather than a program. The European Defence Fundâs âŹ7.3 billion budget for 2021-2027 represents serious money for research and developmentâbut a rounding error compared to what genuine independence would require.
The Fragmentation Dynamic
NATOâs consensus requirement is simultaneously its greatest strength and its most exploitable weakness. Every member must agree before the alliance acts. This ensures legitimacy but creates veto points. Trumpâs transactional approach has weaponized this structure, introducing uncertainty about American commitment that different European states interpret differently.
The fault lines are geographic and historical. Eastern European statesâPoland, the Baltics, Romaniaâview Russian aggression as existential and American protection as essential. They have responded to Trumpâs pressure by increasing spending and seeking bilateral reassurances, essentially treating NATO membership as necessary but insufficient. Their strategy is to become so valuable to Washington that abandonment becomes unthinkable.
Western European statesâFrance, Germany, the Benelux countriesâview American unpredictability as the primary threat to European security. They have responded by accelerating discussions of European alternatives: enhanced EU defense cooperation, Franco-German military integration, the resurrection of the Western European Union concept under different names. Their strategy is to build capabilities that could function without American participation.
Southern European statesâItaly, Spain, Greeceâface different threat perceptions entirely. Their security concerns center on migration, instability in North Africa, and economic competition. They have responded to burden-sharing pressure with rhetorical compliance and minimal actual increases. Their strategy is to wait out American demands while preserving fiscal space for domestic priorities.
These divergent responses do not constitute fragmentation in the dramatic sense of alliance collapse. NATO continues to function. Article 5 remains formally operative. But the alliance increasingly resembles what scholars call âinstitutional isomorphism without substantive convergenceââeveryone uses the same language while meaning different things.
The Strategic Compass adopted by EU member states in 2022 illustrates this dynamic. It commits to âan ambitious plan of action for strengthening the EUâs security and defence policy by 2030â and to making âthe EU a stronger and more capable security provider.â It does not specify how this relates to NATO, whether EU capabilities would duplicate or complement alliance structures, or what happens when EU and NATO priorities conflict.
The Nuclear Question
Beneath the spending debates and capability gaps lies a more fundamental issue: nuclear deterrence. American extended deterrenceâthe commitment to use nuclear weapons in defense of alliesâhas underpinned European security since the 1950s. Trumpâs transactional approach has called this commitment into question without explicitly repudiating it.
The result is a strategic uncertainty that no amount of conventional rearmament can resolve. As analysis from the Martens Centre argues, âWhy Europe Needs a Nuclear Deterrentâ has become a serious policy question rather than an academic exercise. France possesses approximately 290 nuclear warheads. Britain has roughly 225. Neither arsenal was designed to deter Russia from attacking Eastern Europe, and neither country has indicated willingness to extend its nuclear umbrella to cover NATO allies.
The technical and political obstacles to a âEurodeterrentâ are formidable. The Bulletin of the Atomic Scientists notes that the Non-Proliferation Treaty âprohibits nuclear-weapon states from transferring nuclear weapons or control over them âdirectly or indirectly.ââ France could not simply extend its deterrent to cover Poland without fundamental restructuring of its nuclear doctrine, command arrangements, and targeting priorities.
Yet the discussion has shifted from whether to how. German strategists who once considered nuclear weapons taboo now debate scenarios for European nuclear sharing. Polish officials who once championed NATOâs nuclear umbrella now explore what indigenous capabilities might be necessary if that umbrella collapses. The psychological barrier has cracked, even if the practical barriers remain.
This represents the most dangerous potential outcome of Trumpâs burden-shifting strategy. Conventional rearmament is expensive and slow but reversible. Nuclear proliferation is irreversible. Once European states conclude that American extended deterrence is unreliable, the logic of nuclear acquisition becomes compelling regardless of treaty obligations or alliance commitments.
Germanyâs position is particularly significant. As analysis of German strategic culture suggests, the countryâs commitment to the NPT functions partly as psychological repression of its militaristic historyâwhat one might call the suppression of the âPrussian Id.â If that repression fails, if German elites conclude that nuclear weapons are necessary for national survival, the entire European security order transforms.
The timeline matters. Nuclear weapons programs require years to decades. The uncertainty Trump has introduced into American commitments operates on electoral cyclesâfour years, perhaps eight. European states face a temporal mismatch between the threat (immediate) and the response (gradual). This mismatch creates pressure for hedging strategies that preserve nuclear options without triggering immediate proliferation concerns.
The Structural Bind
Europe confronts a strategic dilemma with no clean resolution. Increased defense spending is necessary but insufficient. Genuine strategic autonomy would require industrial mobilization on a scale no European government can politically sustain. Nuclear independence would require either French willingness to extend its deterrent (unlikely) or German willingness to acquire nuclear weapons (transformative). Alliance cohesion requires American reliability that Trump has explicitly questioned.
The most likely outcome is not dramatic rupture but gradual degradation. NATO will continue to exist. European defense spending will continue to rise. Capability gaps will narrow but not close. Nuclear discussions will intensify without producing new arsenals. The alliance will function well enough to deter opportunistic aggression but poorly enough to invite probing and pressure.
This is not failure in the conventional sense. It is the new normal: an alliance that works most of the time, for most purposes, but cannot be relied upon in extremis. European states will hedge accordingly, maintaining NATO membership while building alternative arrangements, investing in American systems while funding European alternatives, affirming nuclear non-proliferation while preserving latent capabilities.
The burden has shifted. Whether Europe can bear it remains uncertain.
What Would Change the Trajectory
Three intervention points could alter this dynamic, though each carries significant costs.
First, American strategic clarity. A future administration could explicitly reaffirm extended deterrence, restore predictability to alliance management, and accept that burden-sharing is a process rather than a transaction. This would require abandoning the leverage that unpredictability provides and accepting that European spending increases will plateau below American preferences. The political cost within the United States would be substantial; the strategic benefit would be alliance preservation.
Second, European industrial mobilization. The EU could treat defense production as it treated COVID vaccine productionâa continental emergency requiring unprecedented coordination, investment, and regulatory suspension. This would require Germany to accept permanent defense spending above 3% of GDP, France to accept genuine European control over defense industrial policy, and smaller states to accept specialization rather than duplication. The fiscal and political costs would be enormous; the strategic benefit would be genuine capability.
Third, French nuclear extension. Paris could explicitly extend its nuclear umbrella to cover Eastern European allies, accepting the doctrinal, operational, and political complications this would entail. This would require France to abandon its tradition of nuclear independence, accept targeting constraints it has historically rejected, and integrate its deterrent into alliance structures. The sovereignty cost would be fundamental; the strategic benefit would be European nuclear credibility.
None of these interventions is likely. American politics rewards unpredictability. European politics rewards incrementalism. French politics rewards independence. The structural incentives point toward continued muddling through.
FAQ: Key Questions Answered
Q: Will European NATO members actually sustain higher defense spending? A: The trend is real but fragile. Twenty-three members now meet the 2% target, driven by Russian aggression more than American pressure. Sustaining these levels requires domestic political consensus that does not yet exist in most countries. Expect spending to plateau around 2.5% for frontline states and drift back toward 2% for others once immediate crisis perception fades.
Q: Could France really extend its nuclear deterrent to protect Eastern Europe? A: Technically possible but politically improbable. French nuclear doctrine emphasizes national survival, not alliance defense. Extending deterrence would require fundamental changes to targeting, command arrangements, and strategic culture. Emmanuel Macron has floated the concept repeatedly without committing to specificsâa pattern suggesting rhetorical positioning rather than policy intent.
Q: What happens to NATO if Trump wins a second term? A: NATO survives but transforms. The alliance would increasingly function as a framework for bilateral deals rather than collective defense. European states would accelerate hedging strategiesâmaintaining NATO membership while building alternative arrangements. Article 5 would remain formally operative but practically uncertain, creating a gray zone that adversaries could exploit.
Q: Is Germany likely to pursue nuclear weapons? A: Not in the near term, but the taboo is weakening. German strategic elites now discuss nuclear options that were unthinkable five years ago. The constraint is psychological and historical rather than technical or economic. If American extended deterrence collapses definitively, German nuclear acquisition becomes a serious possibility within a decadeâa transformation that would reshape European security fundamentally.
The Mirrorâs Edge
The phantom limb still hurts. European defense ministries feel the absence of capabilities they assumed would always be provided. European publics feel the absence of security guarantees they never questioned. European leaders feel the absence of an ally they thought they understood.
Trumpâs burden-shifting strategy has achieved its immediate objective: European defense spending is rising. It may yet achieve its secondary objective: reduced American costs for European security. What it cannot achieve is what American strategists once assumed burden-sharing would produceâa stronger, more cohesive alliance capable of deterring great-power aggression.
The choice Europe faces is not between rearmament and fragmentation. It is between different forms of dependence: continued reliance on an unpredictable America, or new reliance on untested European arrangements. Neither option provides the security that the old order promised.
The limb is gone. The pain remains. And the brain must learn to map a different body.
Sources & Further Reading
The analysis in this article draws on research and reporting from:
- NATO Defense Expenditure of NATO Countries (2014-2025) - Official NATO statistics on alliance defense spending trends
- Atlantic Council NATO Defense Spending Tracker - Real-time tracking of member state contributions
- Small Wars Journal on NATO Burden-Sharing - Analysis of political rhetoric versus strategic reality
- Martens Centre Research on European Nuclear Deterrent - Policy case for European nuclear options
- Bulletin of the Atomic Scientists on Eurodeterrent - Counterarguments to European nuclear proliferation
- NIPP on German Nuclear Musings - Analysis of shifting German strategic culture
- Taylor & Francis on NATO Concept Development - Research on institutional transformation in European defense
