BRUSSELS – European Union leaders are expressing strong disapproval, using words like “intimidation,” “threats,” and “blackmail,” in response to U.S. President Donald Trump’s recent threats. Trump has warned of imposing new tariffs on countries that oppose U.S. ambitions to control Greenland.

The tone in Europe has notably shifted over the past year since Trump resumed office. His administration’s latest stance presents a scenario previously considered impossible: a NATO leader threatening to annex another ally’s territory. If Trump proceeds with his tariff threats, Europe is expected to retaliate with trade measures of its own.

With Trump 2.0 well underway, Europe’s confidence in the transatlantic alliance is rapidly waning. For some, trust has already evaporated. Past attempts at diplomacy have fallen flat, prompting European nations to rethink their strategies as they navigate tensions with a former ally while facing an increasingly aggressive Russia.

During Trump’s first term, NATO nearly faced dissolution. In his recent memoir, former Secretary-General Jens Stoltenberg recalled his fear that NATO might cease to function after Trump threatened to exit a 2018 summit.

Danish Prime Minister Mette Frederiksen has issued a stark warning: any move by Trump to annex Greenland, a semi-autonomous region of Denmark, would halt all cooperation, including within NATO.

According to Maria Martisiute, an analyst at the European Policy Centre, “We are witnessing the onset of a significant political-military crisis.” She notes a growing awareness, albeit reluctantly acknowledged by political leaders, that the U.S. might have turned its back on NATO.

Reading the riot act

In January 2025, U.S. allies at NATO were waiting to hear Trump’s plans for Ukraine.

Europe’s biggest land war in decades was about to enter its fourth year. The Europeans believed that President Vladimir Putin would pose an existential threat to their territory should Russia win.

Few thought that Biden administration policies would continue. But within weeks, any lingering hopes for the U.S. commitment to Ukraine dissolved. American arms supplies and funds began to dry up. Europe would have to fill the gap and pay for U.S. help.

In a speech at NATO headquarters in February, U.S. Defense Secretary Pete Hegseth read the riot act to European allies and Canada. The United States had priorities elsewhere and Europe must handle security in its own backyard.

Ukraine would not join the alliance. Its territory seized by Russia would not be returned. The Europeans could pull together a force to help Ukraine if they wanted, but they wouldn’t get U.S. help if they went into the country and got attacked.

Trump has since blamed Ukrainian President Volodymyr Zelenskyy for the invasion.

Days later that February, in Munich, Vice President JD Vance met the leader of a far-right party during election campaigning in Germany. He claimed that Europe’s main threat was internal, not Russia. Free speech is “in retreat” across the continent, Vance warned.

But after winning the poll, Chancellor Friedrich Merz, said that “in view of the increasing threat situation,” Germany and Europe “must now very quickly make very big efforts, very quickly,” to strengthen their defense capabilities.

Europe’s security independence

Over the course of last year, European leaders and Zelenskyy flew to Washington to try to keep Trump onside. A 28-point plan to end the war that he floated would acquiesce to many Russian demands.

The plan was reworked. Talks continue, but without Putin. Few expect him to accept. Trump mostly blames Zelenskyy for the stalemate.

Meanwhile, Europe pressed ahead with new defense measures, even as Trump waged a global tariff war, including against U.S. allies, roiling their economies.

The EU created a multibillion-euro fund to buy arms and ammunition, with the emphasis on sourcing them from European companies and weaning nations off U.S. suppliers.

Debt rules were eased for security spending. Money was funneled into Ukraine’s defense industry. In December, European leaders agreed to pay for most of its military and economic needs for the next two years as Kyiv teeters on the brink of bankruptcy.

A new U.S. national security strategy further soured transatlantic relations. It paints European allies as weak, offers tacit support to far-right political parties, and criticizes European free speech and migration policy.

European Council President Antonio Costa warned the U.S. against interfering in Europe’s affairs. Merz said that the U.S. strategy underscores the need for Europe to become “much more independent” from the United States.

Work has since begun on Europe’s own security strategy. It aims to respond to “the geopolitical changes in our world and to give an appropriate answer to that,” European Commission President Ursula von der Leyen said.

Part of it is to make Europe even more autonomous.

As France, Germany, the U.K., Norway, Sweden and the Netherlands sent troops to Greenland last week — small in number but highly symbolic in the message of resolve sent to the White House — French President Emmanuel Macron said that it’s important “to stand at the side of a sovereign state to protect its territory.”

“Europe is being shaken from some of its certainties,” he told French military chiefs. “It sometimes has allies that we thought were predictable, fearless, always by our side, who are now causing us to doubt a lot, or are even turning against those who expected it the least.”