Can Trump Actually Quit NATO? We May Soon Find Out

On April 1, President Donald Trump told the Telegraph he’s “strongly considering” pulling the United States out of the North Atlantic Treaty Organization, calling the alliance a “paper tiger,” and tying that hostility explicitly to Europe’s refusal to back his ill-conceived war against Iran. Secretary of state Marco Rubio echoed that sentiment when Spain outright refused US military overflights tied to the Iran war. At the same time, defense secretary and middle school bully Pete Hegseth declined to reaffirm NATO’s collective defence guarantee when asked directly, saying the decision was “up to Trump.”

Throughout 2025 and early 2026, you might have thought, perhaps optimistically, that the damage from those kinds of statements could be undone. It might take generations, but surely, someday, the US would regain the trust of friends and allies. That optimistic thinking, however, assumes that World War III doesn’t happen first.

So, could Trump unilaterally pull the US out of NATO? Congress tried to lock this door after Trump’s first term. Section 1250A of the 2024 National Defense Authorization Act says the president may not suspend, terminate, or withdraw from the North Atlantic Treaty without two-thirds Senate consent or an act of Congress.

Why would Congress do this? Doesn’t the US constitution already require two-thirds Senate consent for treaties? Yes, Article II clearly says how the US enters a treaty: the president makes treaties “by and with the Advice and Consent of the Senate,” with two-thirds of senators present concurring. But the constitution is silent on how the US withdraws from one.

So, the 2024 NDAA rule was Congress trying to fill a gap and block a president from claiming, “Sure, the Senate helps me get into treaties, but I can get out of them alone.” Also, NATO’s own treaty gives a one-year notice window before withdrawal takes effect, so leaving wouldn’t be immediate—in theory.

All of this sounds reassuring, but it’s basically a home security sticker on a first-floor, single-pane window. Here’s the problem: a president doesn’t need a clean, lawful exit to damage deterrence. He can erode it in place. He can turn NATO into a shell company with a headquarters in Delaware, a shitty AI-generated logo, and a stock price in free fall.

He can slow-walk deployments, freeze planning, undercut exercises, refuse to reaffirm Article 5, and make every crisis feel conditional on what you’ve done for him lately.

If Trump actually tried an overt unilateral withdrawal and Congress fought back, that case would likely land at the Supreme Court faster than you can say “ground war in Iran.” And I’m not betting the mortgage that the current conservative majority court wakes up every morning asking how best to frustrate Trump’s Article II ambitions.

A presidential-power reading that favours unitary executive authority over statutory limits is a live option. But here’s the part that actually keeps me up at night, and I mean that less metaphorically than it sounds: A formal US withdrawal from NATO would be catastrophic. Markets freak out, Europe goes through a vulnerable transition period, and journalists take the word “historic” and run it into the ground with every Substack post.

But a half-detached America might actually be worse because it leaves NATO’s institutional shell standing while quietly hollowing out the confidence that made it matter at all.

NATO works because Article 5 is a promise backed by US nuclear assurance, strategic lift, intelligence, air and missile defence, maritime power, and the assumption that Washington won’t turn every emergency into a protection racket.

NATO secretary general Mark Rutte said in March that the US umbrella remains the “ultimate guarantor” of European security. You can’t replace American nuclear assurance and command weight by buying more Gripens.

But Europe’s situation is not hopeless.

Reuters reported on March 26 that NATO’s European members and Canada increased defence spending by 20 percent in 2025. Poland, Lithuania, and Latvia have already passed the 3.5 percent gross domestic product benchmark for core defence spending.

Europe has real armies, real shipyards, real air forces, and very real memories of what happens when the continent’s security architecture collapses. It gets cities full of ghosts.

But money isn’t coherence. That’s the part everyone keeps skipping over.

European security without US backing lives or dies on coherence, like shared command, common procurement, interoperable air defence, logistics that work under fire, clear nuclear signalling, and a front-line posture that convinces Moscow the cost of testing the alliance is still insane.

So, what does that actually look like if Trump either pulls out or effectively gut-punches NATO from inside?

Europe needs a real, local operational core ASAP. The alliance would need a hard centre of gravity built around Britain, France, Germany, Poland, and the Baltic-Nordic states, with Romania on the southeastern flank and Canada still plugged in wherever it can.

Britain and France bring nuclear capacity and strategic culture. Germany brings industrial weight and central geography. Poland and the Baltics bring urgency. Europe needs to stop treating eastern-flank states like the smoke detector in the basement and start treating them like the people who smell the fire first, because they actually live in the house.

This includes battle management, secure networks, planning structures, and the general ability to stitch multinational forces into one fight instead of twenty-seven separate national performances.

The Center for Strategic and International Studies has made the broader point that Europe’s problem is not just platforms. It is the enabling architecture that lets those platforms operate together at scale. This has been a US capability for the past fifty years. Europe will need to fill the gap.

Also, Europe needs to settle the nuclear question faster than anyone’s political comfort zone allows. If the US leaves, France becomes central whether Paris wants the role or not, and Britain’s independent deterrent becomes even more politically important.

This won’t be easy. Nuclear politics in Europe can devolve into emotional street mime performance art in about six seconds. But there’s no credible deterrence strategy without a credible nuclear umbrella, and if the American one starts packing up, Europe needs to get serious fast.

Europe also needs integrated air and missile defence on a scale it still doesn’t fully possess. Early warning, layered interceptors, common tracking, shared command networks, deep stockpiles. Ukraine has already taught anyone willing to pay attention that missile defence is a core survival function.

Europe needs to fix its procurement culture. I’ll use the technical term: it needs to un-fuck it.

The continent spends more than it used to, but too much of that spending still moves through national silos and procurement politics that treat interoperability like a joke. NATO officials have warned explicitly about allies failing to buy enough weaponry together.

If the US steps back, Europe doesn’t have time for every capital to reinvent the armoured vehicle, the artillery shell, and the radar program out of national pride. This means common purchases, common standards, ammunition production, missile production, and industrial surge capacity. This is the boring stuff people skip to get to the dramatic map graphics, but it’s exactly the stuff that decides whether deterrence is real or decorative.

I’m not saying every European country needs to adopt the exact same tank. This introduces its own problems. Let’s say Russia finds a vulnerability it can exploit in the Leopard tank. If everyone is fielding the Leopard, your whole fleet across all of Europe is buggered. But a degree of uniformity is required.

Europe needs forward defence that actually looks forward. Poland, the Baltics, Romania, Finland, Sweden, and Norway all matter even more in this scenario, not as symbolic tripwires but as the backbone of a posture meant to make any Russian probe instantly expensive.

Then there’s strategic and theatre airlift. No one can deny that the US can move equipment around the globe pretty quickly. Europe’s independent heavy airlift capacity is limited. That means Europe would struggle more without US transport aircraft and the broader US logistics machine behind them.

Moving forces is not a side issue. If you can’t move them, you don’t really have them.

But there’s one central problem with all of that, and it’s the thing I can’t talk my way around. Europe can build a stronger autonomous defence posture over time. What it can’t do is instantly replace decades of American command and control, ISR (intelligence, surveillance, and reconnaissance), nuclear assurance, strategic lift, and logistics.

That gap is exactly where Russian president Vladimir Putin would be most tempted to test the alliance. Not necessarily with a full conventional invasion of a NATO state (although it’s possible). More likely through coercive probes, limited military intimidation, engineered crises, sabotage campaigns, and cyber pressure meant to discover whether a US-less NATO still has a functioning nervous system.

That’s why Trump doesn’t need a Supreme Court victory to weaken deterrence. He only needs to make Moscow believe the alliance has become conditional.

There’s a domestic politics dimension here, and it runs straight through the November midterms. I’ll be careful not to call a blue wave before it exists, because American politics has a long tradition of humiliating people. But Reuters and Ipsos found recently that 66 percent of Americans want a quick end to the Iran war, even if the administration’s goals aren’t achieved, and 60 percent disapprove of the strikes.

That’s terrible political terrain for the party that started the war, especially if gas prices stay high and the body count keeps growing. If Democrats retake even one chamber, a formal NATO exit gets harder, procedurally and politically. Trump could still act destructively through executive action, but the clean, legal rupture gets narrower.

The catch is that Europe can’t wait on the midterms. It has to assume that, for at least the next several months, Trump could bully NATO, starve it, or challenge the statutory limits Congress put on his withdrawal power.

You don’t get to defend a continent by hoping Ohio goes your way.

Now, the Ukraine question. If the United States leaves NATO, does that make Ukraine more or less likely to gain admission? Short term: less likely. Almost certainly.

I know that sounds backward. You could imagine a more European NATO deciding to harden itself against Russia by bringing Ukraine in, especially given Ukraine’s battlefield experience, size, and strategic position.

That case exists, and I take it seriously. Ukraine has done more in blood and military adaptation to qualify as a genuine security contributor than most NATO members have done in decades. Anyone who’s watched Europe sleepwalk through defence for twenty years and then watched Ukrainians improvise a modern combined-arms military under bombardment should be honest about who’s been teaching whom here.

But alliances don’t admit new members during institutional panic unless they’re absolutely certain it strengthens deterrence immediately. A NATO reeling from US withdrawal would first be focused on internal coherence, nuclear arrangements, command structures, and convincing itself it can survive the transition. That’s not the environment in which a nation with an active territorial dispute glides in on a red carpet.

There is one exception and possible pathway. Let’s say the US leaves NATO, and Putin decides to take advantage of the disarray and quickly and moves into Latvia or another Baltic state. At that point, the remaining NATO members (let’s call them Euro-NATO) would be forced to fight Russia, making Ukraine and Euro-NATO military allies in everything but name. In that scenario, Euro-NATO may as well just say extraordinary times call for extraordinary measures and admit Ukraine.

The current US posture is already making Ukraine’s path harder. On March 25, President Volodymyr Zelenskyy said Washington was linking security guarantees to Ukraine giving up the Donbas, a claim Rubio later denied, though the episode itself illustrates how the Trump administration treats Ukraine as a bargaining chip rather than a future pillar of European security. Even without a NATO rupture, that’s a bad sign.

The longer-term counter-argument is worth sitting with though. A more explicitly European NATO, one that sees itself as a continental anti-imperial defence bloc, rather than a US-anchored, transatlantic system, would almost certainly find Ukraine more attractive, not less. Ukraine brings a massive army, hard-earned drone-warfare expertise, missile defence lessons written in blood, and a strategic culture no European military college can manufacture.

In a Europe that’s finally stopped outsourcing its security to Washington, Ukraine could look less like a burden and more like one of the strongest arguments for why the alliance still matters.

• Bad as Trump Is, What Follows Him May Be Worse
• Trump Tests the Limits of American Power in Iran
• Canada Is Already at War with the US—We Just Don’t Know It Yet

But that’s chapter three in this nightmarish choose-your-own-adventure book. We have to get through chapter one first. Chapter one is a dangerous transition where deterrence weakens faster than Europe can rebuild it, Russia watches for seams, and Ukraine’s formal path into NATO slows because the alliance is busy triaging itself.

And that’s what makes all of this so genuinely insane. This is an attempted rupture of the most important military alliance in modern history at a moment when Russia is still trying to break Ukraine, the US is on the eve of deploying ground troops in another godforsaken desert war, and China is benefiting from its highest international favourability ratings since the Ming Dynasty.

Trump keeps treating alliances like tenants in a building he owns. Pay me more. Back my war. Say thank you louder.

Some of those tenants, like Canadian prime minister Mark Carney, have kindly told the landlord (in a roundabout way) to quietly and vigorously go fuck himself.

What Trump doesn’t really understand is NATO is an insurance policy written in steel, logistics, nuclear deterrence, and the kind of European flora that only grows in soil that is nourished with the buried bodies of millions of people across two world wars.

Europe knows what happens when the continent’s security architecture collapses. It doesn’t need another history lecture. I think Europe can certainly build more ammunition lines, more brigades, more missile defence, and more institutional coherence. What it can’t manufacture is time.

Which means it needs to start thinking about this now—not at a committee meeting this August. Not sometime in May. There needs to be an Apollo program started yesterday for European unity in the face of a now hostile United States.

As for whether Trump means what he says when he threatens to pull the US out of NATO, I think we’ll know the answer sooner than we realize.

Originally published as “Can Trump Unilaterally Pull America Out of NATO? Europe May Soon Find Out” by Wes O’Donnell (Substack). Reprinted with permission of the author.