NATO may be entering a new era, with both the United States and its European allies signalling that the balance of responsibility within the alliance needs to shift. While Washington wants to free up resources to focus on other regions, European leaders appear increasingly ready to take on a larger share of the burden — though their motivations are not entirely the same.
At a meeting of NATO defence ministers in Brussels, US Under Secretary of War Eldridge Colby called for what he described as “NATO 3.0.” In his view, the alliance must evolve so that European nations assume primary responsibility for the continent’s conventional defence.
Colby argued that Europe should provide the bulk of the forces needed to deter — and, if necessary, defeat — aggression on its own soil. The United States, he suggested, cannot continue carrying the lion’s share of that responsibility.
Europe Signals a Shift in Mindset
The American call for greater burden-sharing is not new. For years, Washington has urged its allies to spend more on defence, particularly as it seeks to shift attention toward the Indo-Pacific. What felt different this time was the response from European leaders.
NATO Secretary General Mark Rutte described the meeting as one of the most significant he has attended, pointing to what he called a genuine change in attitude. He highlighted a noticeable increase in defence spending across the alliance in 2025, with countries such as Denmark, Estonia, Latvia, Lithuania and Poland already surpassing the newly agreed 3.5% of GDP defence target — well ahead of schedule.
That target was agreed upon last summer after repeated comments from US President Donald Trump raised doubts about America’s automatic commitment to NATO’s collective defence principle, especially for members failing to meet spending goals.
Germany’s Defence Minister Boris Pistorius acknowledged that the US has long carried most of the responsibility for Europe’s conventional defence. He said it is now natural for European countries to gradually assume more control in the years ahead. France’s Catherine Vautrin echoed that sentiment, noting that efforts to strengthen NATO’s European pillar are already underway.
Romania’s Radu-Dinel Miruță stressed the need for Europe to expand its defence production capacity, ideally in coordination with NATO and the US — but with a clear aim: Europe must be capable of protecting itself.
Tensions and Trust Across the Atlantic
Recent events have added urgency to the debate. Just weeks before the Brussels meeting, President Trump threatened military action against Denmark, a NATO ally, over Greenland. In response, NATO launched enhanced vigilance activities in the Arctic while diplomatic talks between Denmark, Greenland and the US continue.
Dutch Defence Minister Ruben Brekelmans called for transparency between both sides of the Atlantic, advocating a “no-surprise policy” so that any reduction in US military presence would be matched by a clear European plan to fill the gap.
Some of that rebalancing has already begun. The US recently announced it would not replace an infantry brigade in Romania after its current rotation ends, signalling a gradual drawdown. At the same time, European nations have assumed more leadership roles within NATO’s command structure.
However, certain positions remain firmly American. While Europeans now lead the alliance’s three joint force commands, the role of Supreme Allied Commander Europe — responsible for NATO’s military planning — is still held by a US officer. Rutte defended that arrangement, arguing that maintaining an American in that position ensures a continued and credible US presence in Europe.
As the world shifts and new threats emerge, NATO appears to be adjusting. Whether this “NATO 3.0” will strengthen transatlantic ties or test them further remains to be seen, but one thing is clear: the alliance is redefining what shared responsibility truly means.
