The Transatlantic Relationship You Knew Is Gone

Since Iran began targeting commercial shipping and reportedly mining the Strait of Hormuz in retaliation against the unfolding U.S. and Israeli war, President Trump has attempted to galvanize U.S. allies, partners, and adversaries alike to join the U.S. military in ensuring freedom of navigation. But the attempt has gained little traction, with allies largely rejecting Trump’s demands. In response to a question about whether he is considering leaving the alliance, the reportedly furious president said, “Well, I’m disappointed in NATO. I don’t need Congress for that decision … I can make that decision myself,” despite legislation preventing any president from withdrawing from NATO without congressional authorization. Trump’s ire for U.S. allies over Iran is not an isolated incident of allied disagreement; instead, it is part of an accumulating structural shift in alliance behavior. 

In response to the crisis in the alliance over Trump’s threats to annex Greenland, Gov. Gavin Newsom (D-Calif.) had attempted to reassure U.S. allies at the 2026 Munich Security Conference, telling European leaders in February, “Donald Trump is temporary. He’ll be gone in three years.” This message was familiar. After the 2020 election, the Biden administration reassured allies that U.S. foreign policy had returned to its pre-2016 trajectory. Allied governments treated President Biden’s reassurances positively but cautiously, concerned by the potential for swings in U.S. policy at least every election cycle.

In recent years, U.S. policymakers have often treated credibility with allies as renewable: A new administration recommits to alliances after coming to power, and trust is therefore restored. But expectations no longer reset after an election. Instead, a pattern of repeated U.S. policy reversals across administrations in recent decades (accelerated since the first Trump administration) has altered how allies interpret U.S. politics. Now, allies are coming to view U.S. political volatility as a structural condition, not a one-off aberration. Instead of waiting for stability, U.S. allies now must plan for its absence.

Future U.S. administrations will inherit not just a damaged NATO but a different one. Renewed European debates over strategic autonomy and attempts to diversify defense procurement reflect a shift from waiting out Washington’s dysfunction to planning around it. The question, moreover, is no longer whether allies must act without the United States, but how they should operate when U.S. policy itself is unpredictable. As Canadian Prime Minister Mark Carney argued at the World Economic Forum in January, “We know the old order is not coming back. … Nostalgia is not a strategy.” The task ahead is not figuring out how to restore NATO as it existed but, instead, navigating how the alliance can function under persistent uncertainty.

Threats Are Not Cost Free

Threats from allied members reshape alliance behavior even when the members do not follow through. European governments have already begun revisiting procurement decisions, trade dependencies, and intelligence practices with the U.S. in anticipation of NATO’s future volatility. Following the height of the Greenland crisis—in which Denmark reportedly pre-positioned blood supplies and planned to blow up runways in preparation for an expected U.S. attack—U.S. commentators and politicians alike have focused too narrowly on the outcome and have missed the crisis’s strategic cost—particularly in the context of broader U.S.-Europe tensions since Trump’s return to office.

Observers dismiss the impact of the crisis because it did not end in an intra-NATO war. They point to the occasional positive speech from administration officials—for example, U.S. Under Secretary of Defense for Policy Elbridge Colby’s speech at the NATO Defense Ministerial on Feb. 12—as evidence that anxieties about the U.S.-Europe relationship are overblown. Yet this intentionally blinkered analysis normalizes Trump’s coercion by framing threats to allies as having zero impact, as long as those threats do not result in war or the administration’s later rhetoric sounds more cordial.

The core issue remains that threats by one ally against the others fundamentally damage trust, which imperils NATO’s cohesion. This is not to say that alliances persist solely because states trust one another. States maintain alliances because it makes defending against common threats more feasible, because states receive benefits from such membership in their own domestic politics, or even because alliances’ institutional scaffolding helps perpetuate them. But damaged cohesion undermines all of those incentives. It will make one of NATO’s core tasks—signaling credible deterrence—more difficult. Capability is not the only factor required for extended deterrence: Damaged credibility undermines both the allied belief that commitments will be honored and an adversary’s belief that threats will be followed through.

There is enough evidence from the escalating set of political, military, and economic crises under the second Trump administration to take the U.S. seriously in its hostility toward NATO allies. As a result, the new status quo will include the deepening of existing crises and the emergence of new ones. Therefore, this dynamic will not disappear because of a peaceful settlement over Greenland or a vaguely conciliatory speech.

Credibility Deficit

For most of its history, NATO has adapted to face evolving security threats while preserving a stable balance of power in Europe. Today, the alliance faces a fundamentally different challenge: A major threat to its cohesion emanates from its strongest member, the United States. To be sure, the transatlantic relationship weathered disagreements and crises before, but the current rupture is qualitatively different in both its source and its implications.

While previous administrations attempted to resolve disagreements inside the alliance via diplomatic means, intelligence sharing, and other methods, the second Trump administration has preferred to skip those time- and labor-intensive steps, and instead issue threats—political, economic, and even military—to make allies bend to its will. The administration has also elevated and seemingly prioritized these intra-alliance disagreements over NATO’s core objectives, including that of deterring Russia. This dynamic means that the allies have less bandwidth to commit to defending against cyber, nuclear, and conventional threats.

The underlying problem is the U.S. and Europe’s diverging perceptions of actual security threats. Europe’s view of the transatlantic security situation is that Russia poses an existential threat, whereas the Trump administration frames Russia primarily as a regional challenge. Recent strategy documents and official statements emphasize the Trump administration’s position that Europe must assume responsibility for its conventional defense, while seeking to downgrade the U.S. conventional footprint on the continent and encourage the diplomatic management of Europe-Russia tensions (while at the same time excluding Europeans from attempts to broker peace between Russia and Ukraine).

This gap in outlook matters: Alliances function best when members’ threat perceptions and understanding of risk are closely aligned. Europe viewing deterrence vis-a-vis Russia as essential to survival and the United States assessing Russia as mainly a regional issue will inevitably lead to a divergence in political expectations, military posture, and tolerance for escalation. In this environment, Europeans will not only question U.S. reliability but also plan for a security architecture in which U.S. commitment is unreliable or conditional rather than foundational.

The next president will be unable to reverse the Trump administration’s damage to U.S. credibility. Trump has gone even further in his first year back in office than he did in his entire first term, when some institutional and personnel guardrails constrained his actions. The situation need not deteriorate to the point of actual U.S. use of force against an ally to cause irreversible and fundamental damage. The alliance could simply become a hollowed-out institution: ineffectual and incapable of meeting its core mandate of deterring threats. When Trump left office in 2021, the damage to alliances was significantly less pronounced than the harm already inflicted over the course of just the first year of his second term. And even so, the Biden administration struggled to convincingly make the case to allies and partners that the anomaly of Trump’s first-term foreign policy was behind them, and a future administration—regardless of party—now faces an even greater credibility deficit.

Across future administrations, U.S. leaders will have to demonstrate to allied governments and citizens alike that the United States is an ally rather than an adversary—as Europeans now increasingly view Washington. An emphasis on restoring relations with Europe could also carry political costs for U.S. leaders. Despite the majority of Americans opposing Trump’s actions and viewing NATO as beneficial to U.S security overall, a persistent minority of the population approves of the administration’s approach to foreign policy. Today, allies’ publicly released intelligence assessments characterize the United States as a threat—alarmingly, even among those allies whose populations and governments have a strong pro-U.S. track record.

A Broader U.S.-Europe Deterioration

The crisis in NATO is part of a broader deterioration in U.S.-Europe relations, and allies are hedging beyond defense policy alone. Across an interrelated set of issues spanning ideology, trade, and technology, these frictions reinforce and accelerate the downward trajectory of transatlantic relations. Allied assessments of these frictions are not monolithic, and subgroups within national governments or the European Union advance their own solutions to managing tensions with Washington. As the relationship drifts apart at different speeds and across domains, the result will not necessarily be a clean rupture for the alliance. Instead, NATO will likely endure as an institution while strategic alignment among its members increasingly fragments.

For many U.S. allies, the deterioration is being driven by what allies view as U.S. interference in domestic political affairs, as Trump administration officials parachute in to favor fringe personalities and movements. In Canada’s case, the United States has gone so far as to hold repeated official meetings with separatist groups. The Trump administration is not just intervening in allies’ domestic politics on an ad hoc basis but has embedded this approach in its national security strategy.

During a February speech at the Munich Security Conference, Vice President Vance warned that the greatest threat facing Europe was not from Russia or China but “the threat from within, the retreat of Europe from some of its most fundamental values.” The administration reiterated this argument in its National Security Strategy, warning of “civilizational erasure” in Europe that stems from policies that the administration claims undermine political liberty and sovereignty, permit destabilizing migration, restrict free speech and dissenting viewpoints, and accelerate demographic and cultural decline on the continent. 

President Trump has endorsed candidates in elections, such as in Hungary, as other right-wing or far-right politicians have sought to closely tie themselves to the ideological thrust of the Trump administration in form and function. Meanwhile, the Trump administration has refused meetings—on both sides of the Atlantic—with officials from parties in the political center or farther to the left. Finally, the Department of State is reportedly planning to fund think tanks in Europe that will promote policies favored by the administration. Taken together, these actions highlight that the values that allies believe the alliance was built on are now contested by the alliance’s dominant member.

These ideological frictions intersect with and intensify disputes in trade and technology policy. The Trump administration’s use of tariffs (real or threatened) and its attempts to wield regulatory threats and potential market limitations as political leverage have reinforced to allies that they must wean themselves off U.S. overdependence in critical economic sectors and technological domains. Disagreements over such topics as digital regulation or content moderation have further politicized what used to be largely technocratic problems, with Washington framing these disagreements as free speech issues.

In countries directly targeted by the administration’s coercion—notably Canada and Denmark—these pressures have begun changing domestic politics, although not in ways favorable to the Trump administration. Instead, in many instances, U.S. action has helped crystallize backlash against the United States by strengthening internal support for allies’ leaders and parties committed to resisting U.S. coercion.

U.S. pressure has also pushed allies to renew efforts to resuscitate stalled trade agreements (such as the EU-India “mother of all deals”), revisit stated or unstated limits on engagement with China, and reduce technological dependencies. Ultimately, these steps do not alone portend a full break with the United States but, rather, reflect allies’ desire to manage the growing list of risks allies recognize in their relationships with Washington. Over time, this form of hedging will further undermine transatlantic cohesion.

European allies and Canada cannot switch off their relationship with the United States overnight. The allies’ interests and capabilities are intertwined across political, economic, military, and intelligence priorities. In some cases, given the allies’ reliance on the United States, some of their capabilities have atrophied or were never developed to begin with. But unless major changes occur and the U.S.-Europe relationship fundamentally changes—because of the president leaving office, the administration changing its mind, or Congress pushing to create a bulwark against Trump’s most damaging policies—in the short term, NATO allies will accelerate their attempts to reduce this dependency. 

Partial Backstops

The question is not whether change is coming but who will shape it and how. Congress, U.S. states, nonprofits, and the business community can all provide partial backstops that mitigate the Trump administration’s damage to U.S. alliances. None alone can substitute for the federal government, but together they can help constrain further erosion and signal a continuing U.S. stake in alliances. 

Congress retains unique constitutional powers—such as oversight, appropriations approval, national security authorities, and trade—that could raise the cost of unilateral coercion and impose constraints that transcend turnovers between administrations. In its bipartisan 2026 National Defense Authorization Act (NDAA), Congress provided continuity in U.S. security policy by reaffirming support for U.S. allies and partners. But Congress signaling continuity is not sufficient. Polarization, partisan incentives, and deference to the executive branch have led to Congress failing to translate concern into real constraints on executive action, even as the Trump administration has taken steps to undermine the foundations of U.S. national security policy.

Some residual bipartisan consensus on the centrality of alliances to U.S. national security still exists, reflected in legislation seeking to reassert congressional oversight and to protect alliance commitments. For instance, a provision requiring congressional approval should the executive branch seek to withdraw the United States from NATO was attached to the 2024 NDAA, and bipartisan sponsors in the Senate have sought to prohibit the use of funds from the Department of State or the Department of Defense to support efforts to annex an ally’s territory. The Trump administration, however, has demonstrated that the existence of checks is not enough of a constraint; such checks must include real consequences for violations. To truly be relevant, Congress should implement enforcement mechanisms—including binding funding prohibitions or statutory penalties tied to treaty violations—to impose real political or financial costs rather than continuing to rely on the current checks, which are insufficient at deterring executive branch coercion. 

U.S. states and cities can provide limited but meaningful support for allies that diverge from the federal government’s approach. Although foreign policy is the federal government’s purview, these subnational actors are increasingly seeking to assert themselves, partially mitigating the gaps left by the U.S. government’s selective withdrawal from global leadership. In technology governance, climate cooperation, and public health—among other areas—states and cities are working bilaterally and multilaterally with allied countries. Although states and cities cannot provide a substitute for the federal government or restore alliance credibility on their own, they can help minimize damage by signaling commitment to allies at a time when the federal government’s commitment is far from certain.

The business community is one of the few domestic constituencies with both incentives and leverage—via the potential loss of U.S. jobs and damaged balance sheets—to challenge the Trump administration’s approach to alliance management. Pressure from the business community alone will not be sufficient, and its influences can be indirect or uneven across sectors. U.S. businesses with exposure to the European and Canadian markets stand to lose materially from sustained deterioration in transatlantic relations, not because the companies have a special fondness for alliances, but because a political rupture can translate directly into lost contracts, limitations on market access, retaliatory trade measures, and stiffened regulations. 

These dynamics have already appeared in the defense industry, where U.S. companies stand to lose billions of dollars as allies direct defense spending toward alternative suppliers. Major companies are already banding together in an effort to reassure allies. For example, 16 companies—including Microsoft and Google—launched the Trusted Tech Alliance on the sidelines of the Munich Security Conference, promising “transparency, security, and data protection.” Companies have also offered workarounds for allies concerned about the U.S.’s ability to use a “kill switch” to shut down U.S. technology on allies’ platforms, such as the F-35. However, the effects go well beyond defense companies; new barriers can affect companies in sectors from finance to manufacturing. Stable transatlantic relations have a business logic of their own: Degrading alliance cohesion offers little upside and incurs substantial, durable costs.

NATO at a Crossroads

Absent a course correction, NATO may already be hollowing out. And while this path would avoid the worst-case scenario of a complete dissolution of NATO, it entails considerable risks. Hollowing out will likely make NATO increasingly ineffective both politically and operationally, which will prevent the alliance from fulfilling its objectives of deterring Russian aggression, protecting NATO territory and sovereignty, and supporting Ukraine. Decision-making within the alliance will become slower, plagued by internal fissures, and aspects of alliance integration will be undermined. And with Washington alienating some of its most traditionally pro-American allies, such as Denmark, the United States risks making it more difficult to build and maintain unity when it needs the alliance. This dynamic is apparent in European allies’ refusal to blindly follow the United States into its war in Iran, which it did not coordinate with them. 

The administration’s refusal to engage allies at senior levels will only exacerbate this challenge. In the most recent NATO defense ministerial, where defense ministers from across the alliance gather for high-level discussions, Secretary of Defense Pete Hegseth delegated U.S. representation to the number three civilian leader in the Pentagon. This signals gradual U.S. disengagement and telegraphs to allies that they could also downgrade their representation in the forum (or the foreign ministers’ meeting) in the future. Institutional decay will become self reinforcing, as a diminished but still extant NATO convinces some that survival alone is sufficient. Finally, one of NATO’s greatest strengths lies in the intelligence sharing it enables across 32 nations. Allies viewing the United States as a security threat—such as Denmark—and the administration disengaging from Europe will stymie that core capability. Over time, the combination of these political and operational shifts will contribute to the alliance’s hollowing out, aggravating the challenges that predate Trump’s political life, which have further contributed to the current crisis.

A second future for the alliance is deterioration to the point of near or total collapse. This is the least likely scenario in the short to medium term, but it would have the most impact. NATO’s complete demise would be a significant blow to U.S. and European security. Although such a scenario has a low probability of occurring in the immediate future, it cannot be ruled out in this political environment. 

A third future for the alliance is conscious redesign. This process will not wait for Washington’s permission, and the key question is whether this process will occur with or without the United States. The United States cannot coerce its allies while maintaining credibility, and U.S. leadership must decide what level of autonomy is acceptable. NATO’s center of gravity is already shifting as allied defense investments start to yield dividends. Such a shift may lead to a more limited role for the United States as other allies assume more leadership in the alliance’s conventional power, command structures, and potentially even its nuclear deterrent.

While this may help preserve the alliance and its efficacy, the United States stands to lose the advantages it derives from the alliance’s asymmetric nature if it does not actively work to shape a redesigned NATO. In this scenario, the United States must engage and recast the alliance’s future, shifting the balance toward Europe in a way that still meets its own national security interests.

For Washington, a more fundamental review of the alliance will require more work than simply going through the motions of planning state visits, announcing joint initiatives, and issuing executive orders. Even so, a future administration could prioritize such actions to telegraph to its allies and the world that it will once again place alliances at the heart of U.S. security policy and strategy. Likewise, while recent NATO command changes are a welcome move, they are insufficient to address the structural challenges that are now manifesting themselves within the alliance.

Recasting the Transatlantic Relationship

The question is no longer whether NATO will survive Trump but whether the alliance can survive a United States that has demonstrated a willingness to coerce its allies. Absent deliberate course correction, the alliance’s trajectory toward hollowing out will materially damage both U.S. and European security. Regardless of who succeeds Trump, that administration will inherit a diminished NATO. And as the Biden administration’s experience demonstrated, a reset to the pre-Trump era of U.S. foreign policy will not be possible—particularly as the alliance confronts more internal crises.

If Washington desires more burden sharing, it will have to cede autonomy. If it seeks more control, then it will have to recommit to the continent. But refusing to choose will guarantee the worst of both outcomes. If Washington avoids that choice, it will not inherit the alliance it remembers, but one increasingly less capable of deterring adversaries and less aligned with U.S. strategic preferences.