The United States will conduct a sweeping six-month reassessment of its military footprint in Europe, Defence Secretary Pete Hegseth announced at a tense NATO ministerial meeting in Brussels on Thursday, coupling the review with an extraordinary public rebuke of allies he accused of “shameful” behaviour during the Iran war and decades of “free riding” on American defence spending. The review, Hegseth said, would determine whether the alliance is moving “fast and irreversibly” toward a European-led defence posture, and he warned bluntly that “some countries will fail, and others will pass with flying colours.”

Viewed from Washington, the intervention marks a sharp escalation in the Trump administration’s campaign to force a fundamental rebalancing of the transatlantic security bargain. Hegseth singled out the refusal of several European governments to grant US forces access to bases and overflight rights during the recent military campaign against Iran, calling it a betrayal that “put America’s sons and daughters at risk.” The Pentagon chief also dismissed what he described as a post-Cold War drift toward gender equity, climate change and austerity, insisting the alliance must return to being “a real hardline military alliance” with the conventional capabilities to deter threats on the continent — a vision he labelled “NATO 3.0.”

European capitals absorbed the broadside with a mixture of defiance and anxiety. Italian Defence Minister Guido Crosetto declared that membership in the alliance is not optional: “If you decide to be in NATO, you respect the commitments, otherwise you stay out.” In Berlin, Defence Minister Boris Pistorius warned of “dangerous” capability gaps and urged coordinated planning. NATO Secretary-General Mark Rutte, standing beside Hegseth, endorsed the transformation as “perhaps the largest in NATO’s history” and noted that European allies and Canada had already raised defence spending by $139 billion in 2025, but acknowledged that “enormous efforts” still lie ahead. He described the US review as a structured process that would unfold in close consultation with allies.

From Moscow, the spectacle of a fractious alliance was met with scepticism. A senior Russian lawmaker observed that NATO had always been directed against Russia and predicted that European economies would weaken as they were forced to shoulder a greater share of the financial burden. Meanwhile, analysts in London noted that the review’s outcome remains constrained by the US Congress, which has legislated a minimum troop presence in Europe, and that the process is as much about securing guaranteed access rights as it is about force numbers.

The Brussels meeting has set the stage for a potentially decisive NATO summit in Ankara in early July. Whether the alliance can manage the transition to a European-led defence without rupturing the political cohesion that has underpinned it for seven decades is now the central question. Hegseth’s review will serve as both a pressure tool and a litmus test: European governments must now demonstrate not only increased budgets but also the strategic will to act independently of Washington, even as they remain dependent on American enablers for the foreseeable future.