At the entrance to NATO headquarters, a mangled steel beam from the 107th floor of the World Trade Center’s north tower memorializes the 9/11 attack on the United States. An accompanying plaque notes that within 24 hours, NATO had invoked the alliance’s mutual defense clause for the first time in its history, going to war on behalf of the U.S.
But at a gathering for top NATO defense officials here this week, messages of transatlantic unity were muted as European allies come to terms with the Trump-driven reality that they must now take charge of their own defense.
In Brussels earlier this week, there was lots of talk of “stepping up” as America’s NATO allies detailed moves to increase the supply of weapons, untangle logistical knots, and bring more bullets and missiles to Ukraine’s battlefields.
Why We Wrote This
As U.S. and European security officials gather for key meetings this week, leaders are taking steps to navigate shifts in the traditional transatlantic alliance.
These efforts are bearing fruit: Though the U.S. has almost completely withdrawn direct aid to Ukraine, Europe has come together to fill the gap, according to a report released Wednesday from the Kiel Institute for the World Economy.
NATO officials also announced a new mission to beef up security in the Arctic – a move widely seen as a way to appease President Donald Trump’s demands for control of Greenland, given his reluctance to rule out using military force to get it.
“Basically, it’s important that we collectively understand that [Mr. Trump] has a big point here,” NATO Secretary-General Mark Rutte said at a press briefing here Wednesday. Mr. Rutte has praised President Trump as the catalyst who has forced NATO members to boost their defense budget contributions to meet or exceed the 2% GDP target and commit to 5% by 2035.
Despite cooperative appearances, underlying alliance tensions are expected to follow U.S. and European defense officials to Friday’s Munich Security Conference – where top Democrats like Rep. Alexandria Ocasio-Cortez hope to reassure European allies that Mr. Trump’s opponents see a more effective and collaborative way forward. U.S. Secretary of State Marco Rubio is leading a large delegation and is expected to adopt a more collaborative tone while still defending administration policy.
Still, there’s a prevailing mood within the alliance that some security analysts liken to a married couple “coming to terms with the fact that your partner may not love you anymore,” says Nathalie Tocci, a professor at Johns Hopkins University’s School of Advanced International Studies in Europe.
Some NATO members are grappling with trust issues, she adds. She and others tick off President Trump’s red-carpet reception of Russian President Vladimir Putin in Alaska last summer; Mr. Trump’s comments minimizing the contributions of NATO allies fighting in Afghanistan, setting off protests last month in Denmark (which had the highest per capita casualty rate of any of America’s NATO allies there); and his Oval Office berating of Ukrainian President Volodymyr Zelenskyy one year ago.
“The time will come to reconstitute a different, healthier relationship,” adds Professor Tocci, who has also served as special adviser to two European Union high representatives for foreign policy.
“But you probably need a moment of distance before you can become good friends again.”
Hegseth out, “Trump whisperer” in
Against this backdrop, Secretary-General Rutte was asked Wednesday if U.S. Defense Secretary Pete Hegseth’s absence from this week’s NATO meeting of defense ministers – with Elbridge Colby, undersecretary of defense for policy attending instead – signals a decline in the U.S. commitment to the alliance.
Mr. Colby was a telling choice as the proxy, some analysts said: He has argued that “We have to choose Asia” when prioritizing U.S. military resources, because of the threat from China.
It’s a policy outlook embodied in America’s new National Defense Strategy’s assessment of Russia as a “persistent but manageable threat to NATO’s eastern members.” The report notably did not characterize Moscow as a threat to the U.S. or to the alliance writ large, analysts pointed out.
Mr. Rutte welcomed Mr. Colby to NATO headquarters on Thursday with the sort of rhetorical largesse that has earned him the sobriquet “Trump whisperer” within the alliance.
The defense undersecretary “has been a consistent force over the years for Europe and Canada to really step up when it comes to defense spending,” Mr. Rutte said. The U.S., while a stalwart NATO ally, “also has to take care of the situation in the Pacific,” he added.
Mr. Colby, for his part, lauded the “flexible realism” of his administration’s new National Defense Strategy, for its insistence on an alliance “based on partnership rather than dependency” and a Europe “that leads” NATO’s conventional defense.
The U.S. will continue to provide for Europe under its umbrella of nuclear deterrence, he added.
Arctic Sentry and NATO’s mission
The prospect of Russian forces inching closer to American territory does, however, get the Trump administration’s attention. This was part of the logic behind the Wednesday launch of Arctic Sentry, a NATO military officer said on condition of anonymity. The mission will bring regional drills under a single NATO command to counter Russian and Chinese influence in what NATO officials call “one of the world’s most strategically significant” regions.
If Russian submarines pass undetected through the naval choke point formed by the islands of Britain, Iceland, and Greenland (known as the GIUK gap) and into the deep, open Atlantic, they become much harder to detect.
“It becomes very difficult to track those submarines out there,” the NATO military officer added. “Those submarines then pose a very existential threat to the United States – and also to NATO – because we’re talking about nuclear-capable vessels.”
Others viewed the new Arctic mission merely as a rebranding of NATO’s existing security work in the region. Some reporters pointed out that studies show no Chinese ships lurking near Greenland; NATO officials countered that there soon could be, given the rate at which Arctic ice is melting.
How Ukraine factors in
For now, despite alliance tensions, NATO officials highlight how quickly European members are stepping up to fill the security gap on the continent as the U.S. steps back.
By 2029, for example, Germany will spend $181 billion on defense, more than double what it spent in 2021, Mr. Rutte pointed out Wednesday, adding that it is one example among many.
He also touted this week’s transfer of two top NATO commands from American to European officers and lauded NATO’s newest fund for providing weapons to Kyiv in its fight against Russia’s invasion four years ago this month.
Launched after a July meeting between Mr. Rutte and Mr. Trump, the Prioritised Ukraine Requirements List (PURL) encourages allies to buy weapons from the U.S. for Ukraine.
These weapons are still in short supply as Kyiv comes under increasing fire from Moscow and struggles with desertions among exhausted troops. Russia launched 55,000 drone attacks against Ukraine in 2025, a fivefold increase over the previous year, according to a senior NATO official, who offered background on condition of anonymity. The official added Wednesday that civilian casualties in Ukraine are up 30% over 2024.
Still, while some two-thirds of NATO’s 32 members have committed to joining PURL, others are holding back – a decision that reflects not just budgetary concerns, but also tensions in the transatlantic relationship, analysts say.
France has not contributed to the fund, arguing that it “cannot justify using French taxpayer dollars to buy American weapons while also pushing for Europe’s strategic autonomy,” notes a Chatham House report.
Such concerns come amid speculation by some European diplomats and NATO officials that the U.S. may be downsizing its troop levels in Europe, which have hovered between 75,000 and 105,000 since 2022. The U.S. president last week signaled that those levels would remain steady. Still, the transatlantic relationship remains unlikely to return to the historical status quo, many analysts say, even after the Trump administration ends.
“We know the old order,” Canadian Prime Minister Mark Carney warned last month, “is not coming back.”
