Like other major powers, the United States has long depended on strategic ambiguity, combined with credible military force, to deter its adversaries. The notion that it is helpful to keep an adversary guessing in order to encourage caution and modesty seems relatively straightforward, but it comes with costs. It might also cause an adversary to become anxious, and an anxious adversary might preempt imagined actions or misinterpret signals or behaviors. Thus, strategic ambiguity must be paired with diplomacy and other communication aimed at mitigating those downside risks. Conversely, with allies and security partners, the standard strategic approach tends to focus on reassurance. To enable and encourage long-term cooperation, the United States and its partners and allies mutually reaffirm in word and deed the intentions of their partnerships and clarify their commitments and shared interests to each other.

The behaviors, public statements, and policies of Donald Trump’s administration have perverted America’s strategic posture toward Europe, exchanging reassurance for what might be called “unstrategic ambiguity.” Yes, Europeans have been shocked and horrified to see their most important ally turn confrontational and aggressive. But the real problem is Trump’s opaque intentions. Europeans are reasonably confused about what they can count on the United States for and what they can’t, what the United States really wants, and whether the United States will stay committed to a given strategy long enough for Europeans to plan accordingly.

“We will need a strong Europe to help us successfully compete,” Trump’s December 2025 National Security Strategy says. But the administration’s unstrategic ambiguity is undermining Europe’s strength as a partner to the United States. Even in the best of times, the structure of European decisionmaking requires significant coordination and alignment. With Europeans disorganized following recent U.S. behavior, they are more likely to spend money inefficiently and less likely to arrive at a shared strategy for European defense despite facing their starkest test since World War II. They are missing opportunities to cooperate with each other and to lay the groundwork for Europe’s role as a stronger partner to the United States down the road.

Not Quite Tough Love

Apologists for the administration will often describe Trump’s approach to Europe as one of “tough love,” implying that, like strict parenting, his stance is born out of genuine concern for Europe’s future. But aside from the inherent condescension, the “tough love” explanation cannot explain all of the behaviors to which it is applied.

Tough love—an honest if uncomfortable conversation with a partner—can reset the baseline for cooperation among allies. It may accurately describe a presentation to NATO partners about plans for a substantial reallocation of U.S. military power to the Indo-Pacific that is paired with a demand for European allies to step up and spend more on their own defense in the coming years. Indeed, this sort of tough love has been U.S. policy since at least Barack Obama’s administration and the Wales Summit in 2014, which formalized the commitment by all NATO members to spend 2 percent of GDP on defense. On this point, Trump has been effective in dramatically increasing allies’ commitment to defense spending. All NATO countries, save Spain, agreed last year to increase defense spending to 5 percent of GDP (with 3.5 percent spent on core defense). European regional defense spending in 2025 is over 50 percent higher in nominal terms than in 2014 and accounts for 21 percent of global spending.

But Trump’s repeated territorial ambitions on Greenland, including the use of tariffs and teasing an invasion of the sovereign territory of a NATO ally, is not tough love. It can only be understood as aggressive, adversarial, and coercive behavior. And Vice President JD Vance and Secretary of State Marco Rubio’s cheerleading and formally endorsing radical right parties is akin to the political interference of Russia’s Vladimir Putin in European democracies. This aggression and coercion will destroy the trust that is necessary for cooperation. Look no further than Trump’s Greenland gambit; he gained no concessions from Europe (the Danes had been happy to work with the United States on arctic security and critical minerals before Trump’s moves on the island; they say they are still willing to do so) while burning an enormous amount of trust and goodwill in the process.

After Trump’s first administration, Europeans knew that he could be difficult. Now they must reckon with what has been hitherto unthinkable: America could be dangerous—and could pose a significant, intentional threat to European interests and security. Going forward, when Europeans try to interpret Washington’s positions on defense industrial policy, Ukraine, or China, they will remember that the United States has threatened their sovereignty before. Mixed messages that might previously have been read as bureaucratic incoherence or negotiating positions will take on a more ominous character.

Contradictions on Defense Cooperation

Even granting that the Europeans should dismiss some of the more alarming statements as bluster and assume that the United States and Europe will remain security allies for decades to come, the administration’s messages on the practicalities of security cooperation have caused confusion.

Take defense industrial trade and cooperation. For the last several decades, in return for U.S. security guarantees and high-end military capabilities, European militaries heavily invested in and procured kit from the U.S. defense industrial base. Today, both in response to U.S. coercion from the Trump administration as well as internal calls for Europe to strengthen its military capabilities, European governments are investing in and attempting to build out their own defense industries and reduce certain dependencies on the United States.

This appears to align with the 2026 U.S. National Defense Strategy, which calls on European allies to “take primary responsibility for Europe’s conventional defense.” It would make sense that European militaries and defense industries would become less dependent on the United States as a result. Yet it appears that Washington believes it can avoid this tradeoff. In a public comment on the 2026 revision of the EU Defense and Sensitive Security Procurement Directive, the U.S. Departments of Defense and State claim that the United States “fully supports . . . a revitalization of the European defense industrial base.” At the same time, the administration “strongly opposes any changes . . . that would limit U.S. industry’s ability to support or otherwise participate in EU member state national defense procurements.”

To be blunt, it seems the Trump administration wants Europe to exchange one form of dependence on the United States (the provision of security) for another (reliance on U.S. supply chains to provide European-bought weapons and equipment). It doesn’t want a self-reliant Europe but rather a bigger customer. Given the relative size of the U.S. industrial base, the advent of increased European spending should be a win-win: a flourishing, rapidly expanding European defense industrial base alongside partnerships with and purchases from U.S. defense companies. But with Trump threatening European sovereignty and demeaning European leaders, Europe will focus as much of its increased spending as possible at home and diversify its partners for imports.

It is not yet clear how Washington might react if Brussels pushes ahead with certain provisions that encourage or incentivize joint European procurement—or more explicitly exclude U.S. suppliers. If recent history is a guide, however, the United States will likely attempt to coerce the EU or individual governments into line. This would not only further estrange the United States’ closest security partners but also directly inhibit the stated U.S. goal of a self-reliant Europe for defense. Indeed, part of the problem with a heavy-handed “buy American” push is that in many cases, the U.S. defense industrial base capacity is insufficient for meeting the United States’ own needs. The U.S. government is telling Europeans that they needed to re-arm yesterday while U.S. companies are telling European buyers that they can deliver weapons and vehicles systems in the mid-2030s.

Europe retains multiple kinds of security dependence on the United States: Nuclear deterrence, advanced weapons systems, intelligence and surveillance, and so on. It cannot change all of these dependencies at once. Europe’s “stepping up” in a real way requires an honest conversation with American partners about the timelines for U.S. standing down on specific tasks and inputs to European security. A charitable view of Secretary General Mark Rutte’s sycophancy toward Trump is that the NATO chief aims to appease Trump and avoid complete U.S. abandonment. But this only defers the problem.

And most importantly, this is playing out during the largest war in Europe since World War II. The U.S. administration’s behaviors and policies have spurred a new debate in Europe over whether the continent can rely on U.S. extended nuclear deterrence, overshadowing the conventional challenges Europe continues to face with war raging in Ukraine.

Dissembling or Delusions on Ukraine

Russia’s war against Ukraine is the most important strategic issue for European security. If Russia wins, European security will be forever altered. Conversely, if Ukraine emerges as a sovereign, independent, viable, unambiguously European state, Europe’s security, including its ability to provide for its own defense, is greatly enhanced. European leaders like French President Emmanuel Macron, UK Prime Minister Keir Starmer, and German Chancellor Friedrich Merz, along with EU member states, have collectively and individually taken steps to shore up support for Ukraine, notwithstanding the ongoing obstruction from Hungary’s Viktor Orban, who has become Vladimir Putin’s frequent accomplice within the EU.

But whether the Trump administration will help backstop Europe in its support to Ukraine, especially if a ceasefire is achieved, remains an open question. The United States has indicated a willingness to play a role, but the fickleness of U.S. policy and volatility of Trump’s temper (as demonstrated anew by his recent outburst over NATO allies’ unwillingness to get involved in the U.S. and Israel’s war on Iran) have left them unsure of how to plan for the day after a ceasefire. And when it comes to a prospective ceasefire, Trump has repeatedly claimed that peace is within sight, but most Europeans (and many American experts) see no evidence that Putin is ready to end the war. They are left wondering, is Trump being duped by Putin? Is he planning, as he has mused, to strongarm Ukraine into a deal that would be tantamount to granting Putin a better victory than he might ever achieve on the battlefield? Or is the United States serious about playing a critical role in security guarantees that Ukraine will need, including ongoing access to intelligence and specialized military capabilities?

Europe can only guess for the moment because the administration has largely cut it out of negotiations with Russia and the evolving U.S. approach. Purportedly, the Trump administration wants Europe to take the lead in shoring up Ukraine’s security in the long term. But the Europeans can’t efficiently prioritize their own efforts when the U.S. strategy and its future support are both ambiguous. For Europeans to operate on the assumption of no U.S. support could risk becoming a “self-fulfilling planning process,” where the United States would have contributed but because the Europeans plan for an unreliable U.S. partner, the Americans instead opt out, leaving the Europeans stretched and their security precarious. To achieve maximum effectiveness, Europe needs clarity from Washington on what it sees as a likely endgame, and how they can work together to advance their shared interest in European security.

Missed Opportunity on China

Former president Joe Biden made significant progress throughout his presidency in getting Europeans aligned around the strategic challenge posed by China. Today, from Sweden to Italy, leaders in Europe are united in recognizing that Chinese economic practices and aggressive statecraft pose challenges to European security, democracy, and prosperity.

But the United States now goes against this current. Trump’s decision to go to war with Iran has pulled U.S. military resources from the Indo-Pacific after the United States spent a decade telling European allies that it was refocusing its defense strategy and resources to meet the China challenge. Trump has oscillated between aggressive tariffs on China and obsequious appeals to Xi Jinping, demonstrating an increasing desperation for a bilateral trade deal between Beijing and Washington. He has even decried the EU as a trading partner and declared it “nastier than China.” No wonder that former U.S. ambassador to the EU Tony Gardner, writing in Foreign Affairs, said “Trump has got Europe all wrong.”

As advanced industrial democratic powers, the United States and Europe could be working together to put pressure on China’s unfair economic practices. China is dealing with economic strains of its own; a concerted U.S. and European effort, with support from democratic allies in Asia, could put pressure on the Chinese regime to curb some of its practices while also demonstrating the capacity for united action that might apply in other domains. But given Trump’s oscillation between hard ball and puppy dog postures, the ambiguity of the U.S. position incentivizes Europeans (and others) to cut their own deals with China, potentially with negative repercussions on the security and economic interests of the United States.

It’s Dangerous to Go Alone

At the 2026 Munich Security Conference, Marco Rubio told the audience, “We want Europe to be strong.” Despite his softer tone compared to JD Vance at the 2025 conference, the underlying message has remained the same. When the Trump administration calls for a “strong Europe,” it is not envisioning a partner that builds up independent capacities and works alongside the United States on equal footing. It is calling for a Europe that aligns with Washington’s preferences on conservative cultural issues, defense spending, digital regulation, immigration, and trade.

Across several issues, including defense procurement, Ukraine, and China, Europeans face the same structural problem: U.S. intentions range from opaque to self-contradictory. On defense, Europeans are told to become self-sufficient but also to remain dependent buyers. On Ukraine, they are told to take the lead but are excluded from strategic planning they are meant to support. On China, they are expected to align with the United States but watch Washington oscillate between confrontation and courtship. In each case, this ambiguity actively degrades the outcomes Washington says it wants.

And in addition to these pressing issues, Europeans are still reckoning with and absorbing the longer-term ambiguity resulting from their closest ally going through what many of them regard as the geopolitical equivalent of a psychotic break. “Can Europe ever trust the United States again?” is an already tired seminar and dinner party conversation, but people will keep asking because the obvious answer is so devastatingly depressing and unsatisfying. The U.S. abandonment of decades of settled strategic wisdom around the mutual security and economic dividends of values-rooted alliances cannot be passed off as an anomaly, especially after U.S. voters twice elected a president who has so thoroughly rejected this basic premise of U.S. foreign policy.

The structure of world politics today—aggressive authoritarians in Moscow and Beijing, the erosion of the post–World War II global order—means that European and American citizens would benefit from tighter, deeper cooperation to confront shared challenges. But cooperation requires clarity and reliability. Instead, the Trump administration’s Europe policy appears to be one of ambiguity, which is traditionally reserved for adversaries. The result is a more dangerous world, and one in which citizens on both sides of the Atlantic are less safe and will be less prosperous than they could be. This unstrategic ambiguity is pushing Europe to spend more but coordinate less; it is hedging rather than aligning, and drifting toward fragmented responses to shared threats.