Part I: From Colby NATO 3.0 to the Trump April 1 speech and the threat of withdrawal

In February 2026, at NATO’s defence ministers’ meeting in Brussels, the United States spelled out a strategic shift that had been building for years. Elbridge Colby, serving as Under Secretary of War for Policy, used his intervention to promote what he called “NATO 3.0” – an alliance “based on partnership rather than dependency”, in which European allies assume primary responsibility for Europe’s conventional defence while the United States concentrates on defending the homeland and deterring China in the Indo‑Pacific. The message was unmistakable: the era of automatic American military primacy in Europe is giving way to a more demanding division of labour.

The concept deserves to be taken seriously. But it only makes sense when placed in historical and geopolitical context – and the Trump speech on April 1 has made that task more urgent.

What NATO 1.0 actually was

Colby presents NATO 3.0 as “much closer to NATO 1.0” than to the post‑Cold War model, implying a return from open‑ended expeditionary missions to focused deterrence against a major‑power threat. There is an important truth in that contrast. But it is only part of the story.

NATO was created in 1949 not simply as a military pact but as one pillar of a wider American strategy: that a prosperous, politically stable Western Europe was indispensable to US security and economic interests. The Marshall Plan, launched in 1948, channelled billions of dollars into war‑torn European economies and led directly to the Organisation for European Economic Co‑operation, the OECD’s predecessor. NATO and European economic integration were not accidental twins; they emerged as mutually reinforcing instruments in a broader project to stabilise and rebuild Western Europe.

The intellectual climate of that moment was shaped by voices such as Winston Churchill. In his “Iron Curtain” speech at Westminster College in Fulton, Missouri, on 5 March 1946  Churchill warned that an “iron curtain” had descended across the continent and argued for a durable Anglo‑American partnership as a central pillar of Western security. The speech is widely seen as an early marker of the Cold War not because it glorified confrontation, but because it insisted that shared values required institutionalised, long‑term commitments.

To invoke “NATO 1.0” solely as a lean military instrument is therefore to forget that the original Atlantic bargain was more comprehensive. It rested on partnership and dependency simultaneously: Europeans depended heavily on US power, but the United States also invested heavily in Europe’s capacity to stand on its own feet over time.

From NATO 2.0 to NATO 3.0

Seen from this angle, the post‑Cold War decades – “NATO 2.0” – look like a historical exception. After 1991, the Alliance became a platform for expeditionary operations from the Balkans to Afghanistan, often with the United States providing the bulk of advanced capabilities while many European allies reaped the “peace dividend” at home. Defence spending declined, conventional mass was reduced, and critical enablers such as logistics, strategic lift and air and missile defence atrophied on the European side.

NATO 3.0 is Colby’s label for a deliberate attempt to correct that drift. Three developments frame the debate:

• At The Hague in June 2025, NATO leaders agreed what has become known as the 5 per cent commitment: allies pledged to invest 5 per cent of GDP annually on defence and security‑related spending by 2035, with at least 3.5 per cent for core defence and up to 1.5 per cent for resilience, infrastructure and innovation. The old 2 per cent benchmark becomes a floor, not a ceiling.
• The 2026 US National Defense Strategy organised American defence planning around four lines of effort: defending the US homeland, deterring China in the Indo‑Pacific, increasing burden‑sharing with allies, and “supercharging” the US defence industrial base. Europe is no longer treated as the primary arena of US military power but as one theatre among several where allies are expected to take primary responsibility.
• Colby’s own public remarks translate this into an explicit alliance model. NATO 3.0, as he describes it, is one in which wealthy European allies take the lead for conventional defence in Europe, backed by a continued US nuclear umbrella and selected enabling capabilities.

Taken together, these threads create both clarity and ambiguity. The clarity lies in the direction of travel: higher European defence spending is now embedded in NATO declarations, and US strategic documents openly state that Europe must shoulder the main conventional burden. The ambiguity lies in what this means in practice. How much US conventional presence remains in Europe? Which enabling functions – intelligence, surveillance, strategic lift, air and missile defence, long‑range fires, space and cyber – will Washington still provide as a matter of course? And how will the US nuclear umbrella interact with a more Europeanised conventional posture without eroding deterrence credibility?

From Rebalancing to a Possible Rupture: Trump`s speech on April 1

The ambiguity built into NATO 3.0 crystallised with force in Trump’s primetime address to the nation on 1 April 2026, delivered against the backdrop of Operation Epic Fury – the ongoing US‑Israeli military campaign against Iran launched at the end of February. Formally, the speech was about Iran’s defeat at sea and in the air, but the implications for the Atlantic Alliance were hard to miss.

Trump reported that Iran’s navy had “disappeared”, its air force lay “in ruins”, most of its key personnel were dead, and its missile and drone production had been “blown to pieces”. He promised another two to three weeks of intense operations and threatened to bomb Iran “back to the Stone Age” if the Strait of Hormuz was not fully reopened. In parallel, in an interview with The Daily Telegraph, he referred to NATO as a “paper tiger” and said he was “strongly considering” pulling the United States out of the Alliance after European allies refused to back the Iran campaign. In a separate exchange with Reuters he used the word “absolutely” when asked whether withdrawal was really on the table.

Here it is crucial to distinguish between politics and law. In 2023–24, Congress adopted legislation that explicitly requires a two‑thirds majority in the Senate or a separate Act of Congress for the United States formally to leave NATO. Trump cannot unilaterally terminate the Washington Treaty. But he can, as several analysts have noted, significantly reduce troop presence, withdraw from NATO’s integrated military command, halt funding for NATO bodies and leave key posts unfilled – steps that could de facto hollow out the Alliance even without a formal withdrawal.

Even more telling than the withdrawal threat itself was his treatment of the European allies. For the first time in this conflict, France blocked overflight for aircraft transporting US weapons to Israel; Italy denied the use of Sigonella as a staging base for Middle East operations; Spain both closed its airspace and refused war‑related basing for US aircraft. Germany signalled distance by stressing that this was “not NATO’s war” and that Berlin would not participate militarily in the US‑Israeli operation against Iran.

Trump’s response was scathing: he accused those allies of lacking the courage to stand with the United States and urged European countries facing oil and fuel disruptions to “get some long overdue courage and just take it” themselves. Secretary of State Rubio distilled the logic in a sentence that should give every European capital pause: “If NATO is just about us defending Europe if they get attacked, but they deny us basing rights when we need them, that’s not a very good arrangement.”

This reciprocity logic exposes a structural tension that NATO 3.0 has not fully resolved. The Alliance is, by design, defensive and territorial: Article 5 is about responding to attacks on members’ territory, not about automatic solidarity in global expeditionary operations. It is therefore not self‑evident – legally or politically – that European states must provide unrestricted basing and overflight for every US campaign outside NATO’s area. But it is equally easy to see the domestic political appeal of Trump’s argument to a US audience: we risk our troops for Europe’s security, while they will not stand up for us.

The picture is not entirely one‑sided, however. Throughout 2025–26, Rubio has repeatedly reassured European capitals that the United States is “not leaving NATO” and that stronger European defence capabilities would, in fact, strengthen rather than weaken the Alliance as a whole. The official line in the 2026 National Defense Strategy is not to dismantle NATO but to reshape it: the goal is to “supercharge” the US defence industrial base, deter China, defend the homeland and simultaneously press allies to take “primary responsibility” in their own theatres. It is in this light that NATO 3.0 should be understood – as a rebalancing that risks sliding into rupture.

Lars-Erik Lundin