BRUSSELS - Secretary of State Marco Rubio offered a message of reassurance to his NATO counterparts on Thursday, but also a warning: President Donald Trump remains committed to the alliance, but only if Europe shoulders the burden of its own defense as America turns elsewhere.
In his first visit to NATO headquarters since joining Trump’s Cabinet, Rubio said the U.S. president - who has long voiced skepticism about the 32-member bloc and suggested the United States might not come to the defense of allies - was “not against NATO.”
“He’s against a NATO that does not have the capabilities that it needs to fulfill the obligations that the treaty imposes upon each and every member state,” Rubio said. “... This is a hard truth, but it is a basic one that needs to be said now.”
As the United States seeks to step up its response to China’s military rise, Trump has said NATO allies should raise defense spending to 5% of annual economic output - a transformational leap for many European nations and well above what the United States itself spends.
Rubio’s challenge to NATO foreign ministers came as European nations adjust to dramatic swings in U.S. foreign policy under Trump and as the continent’s key military powers map out how they might replace U.S. responsibilities at NATO to head off a sudden American retreat.
Priorities may diverge
The two-day Brussels meeting represents a high-stakes moment for allies on both sides of the Atlantic who are grappling with the reality that some of their core priorities may irreconcilably diverge. Among the European questions, as they size up Trump’s intentions, is whether his attempt to broker a swift end to the war in Ukraine will hand Moscow a victory that could embolden Russia for years to come.
Rubio’s messages are unlikely to quash questions about the future of the alliance, as the Trump administration excludes Europe from its talks with Russia, threatens to take Greenland from a NATO ally and levies double-digit tariffs on the European Union. And while Rubio’s record suggests support for traditional allies, other top officials, including Vice President JD Vance and Defense Secretary Pete Hegseth, have excoriated Europeans.
The widening rifts have sped up discussions involving France, Britain, Germany and others on eventually replacing U.S. responsibilities at NATO. They want to keep the alliance’s most powerful member engaged, while ensuring that any U.S. military drawdown will be coordinated on a timeline that allows them to bolster their defenses, said five European and NATO diplomats familiar with the discussions.
But the diplomats, who like others spoke on the condition of anonymity to describe sensitive negotiations, said it would take at least five to 10 years and a lot of money to backfill advanced U.S. capabilities. A more muscular European role could involve providing a bigger share of troops to defend the continent, taking over more command-and-control responsibility and developing weapons systems long supplied by the United States.
Other European countries are wary of going it alone or pitching Trump officials a phased handover, concerned it could encourage them to pull back faster - or as one diplomat described it, “that it becomes a self-fulfilling prophecy.”
With less from America, “it would under any circumstances be a very different NATO,” said Camille Grand, a former NATO official who has advised on how European powers can be a stronger “pillar” in the alliance. “We’ve moved from a pure denial,” he said of the European view on U.S. disengagement. “We don’t know whether it’s going to happen in an orderly fashion or fast or chaotically, but it’s going to happen.”
Doing the homework
American officials say the Trump administration has not yet made any decisions about the potential reallocation or reduction of U.S. troops in Europe or U.S. participation at NATO, but the desire to cut costs and downsize military headquarters has reinforced expectations that Washington will curb its footprint on the continent.
“We need to engage them in a conversation on timeline and capabilities. The homework is being done in a number of countries,” said a European diplomat. “When we’ve done that, we’ll see if we can convince others to try to shape this with the U.S. rather than wait for it to land on us in a tweet during the night.”
He said policymakers should “fight the notion that we need to replace every U.S. plane or soldier with a European.
“We should be agile and think, what are the military effects we need to be able to produce very quickly,” he added.
Across the continent, countries that have already ramped up defense spending in recent years are promising to pour hundreds of millions of euros into a military buildup and develop their own systems.
But it would take Europe many years to build up advanced capabilities such as intelligence gathering, heavy airlift, midair refueling aircraft, air and missile defense and long-range precision weapons. The United States also operates air and naval bases across the continent, where up to 100,000 troops have been stationed since Russia’s 2022 invasion of Ukraine.
Reduction of US troops
A NATO diplomat said replacing U.S. capabilities boils down to spending much more on defense - one area where Europeans have found common ground on messaging with Trump. He said a reduction of some U.S. troops would not deal a major blow, as long as a solid presence remains to “still have credible deterrence.”
But other European allies are cautious to even discuss presenting Washington with a plan - some out of habit after decades of dependence on U.S. command in military operations. Others out of fear: Countries near Russia’s borders worry a U.S. retreat would leave them vulnerable.
Officials concede that under the U.S. security umbrella, European governments diverted spending away from defense to other priorities. But they also note that Washington had always urged NATO allies against developing independent capabilities outside the U.S.-led structure.
European officials can foresee taking over posts in NATO’s command structure that have long been held by U.S. officers, but most agree that the role of NATO’s top commander should stay in U.S. hands: the Supreme Allied Commander for Europe, known as SACEUR. “The last American to leave Europe should be SACEUR,” the NATO diplomat said.
The current commander, Gen. Christopher G. Cavoli, is on a three-year term that ends this summer, fueling questions about the Trump administration’s plans.
An attack on one
European discussions are “quite stark behind closed doors when the U.S. isn’t there,” said Michael Carpenter, who served as a senior White House official for Europe during the Biden administration. “They’re talking about the fact that Europe can no longer rely on the United States,” he said, and seeing the U.S. as a power “that they need to contend with in some ways as an adversary, and in some ways, as an unreliable partner.”
On Thursday, Rubio dismissed what he called “hysteria and hyperbole” about a feared American pullback from NATO. But he also cited the continent’s affluence.
“This is a collection not just of partners and allies, but of advanced economies, of rich countries, who have the capability to do more,” he said. “We understand that’s a trade-off. We have to do it every single year in our country. I assure you that we also have domestic needs, but we’ve prioritized defense because of the role we played in the world, and we want our partners to do the same.”
European diplomats said their U.S. counterparts have given reassurances about the commitment to NATO’s mutual defense clause - underpinned by the deterrence of having a substantial U.S. nuclear arsenal based on the continent.
Still, for allies like Denmark, which is grappling with Trump’s threat to take Greenland, by force if necessary, the promise of NATO’s Article 5 - that an attack against one is an attack on all - starts to feel hollow.
As Trump upends decades of U.S. policy on Russia, European policymakers are seeking to understand to what extent the new administration shares their dark assessment of Russian ambitions on the continent.
Despite U.S. reassurances about sticking by NATO, European diplomats have watched with horror as Trump administration officials clashed with Kyiv while sometimes echoing the Kremlin’s rhetoric.
In Brussels, they will again convey to Rubio their red lines for concessions they fear would leave Russia emboldened at their door - such as accepting Moscow’s demands to curb NATO’s posture in Eastern Europe or to scale back the Ukrainian military.
“We’re not at the negotiating table yet. That’s hard to swallow, but that’s a fact of life,” the NATO diplomat said. “We of course have elements where we say this is the baseline and don’t go below it.”