Donald Trump’s first full year back in the White House has brought with it more existential questions for America’s European allies than his entire first term. Trump has made repeated claims that the real threat to European security is not Russia’s Vladimir Putin but Ukrainian President Volodymyr Zelensky, and Trump’s latest fixation is seizing Greenland from Denmark, a NATO ally.

Europeans have bent over backward to accommodate an unpredictable White House and keep Trump on side by agreeing to dramatic increases in their national defense budgets while carefully courting of the U.S. president. In the past year, they have reached deals where European governments would effectively pay the United States to keep weapons flowing to Ukraine and commit their own troops to secure Kyiv’s sovereignty in place of any U.S. guarantees.

Donald Trump’s first full year back in the White House has brought with it more existential questions for America’s European allies than his entire first term. Trump has made repeated claims that the real threat to European security is not Russia’s Vladimir Putin but Ukrainian President Volodymyr Zelensky, and Trump’s latest fixation is seizing Greenland from Denmark, a NATO ally.

Europeans have bent over backward to accommodate an unpredictable White House and keep Trump on side by agreeing to dramatic increases in their national defense budgets while carefully courting of the U.S. president. In the past year, they have reached deals where European governments would effectively pay the United States to keep weapons flowing to Ukraine and commit their own troops to secure Kyiv’s sovereignty in place of any U.S. guarantees.

Over the past fortnight, however, those calculations have changed. Trump, emboldened by his successful capture of Venezuelan President Nicolás Maduro, appears determined to turn his persistent geopolitical fantasies into reality—whether that means invading Greenland or selling out Ukraine.

The most public shift in European thinking came this week, when Andrius Kubilius, the European Union’s defense commissioner, publicly floated the idea of a European Security Council, comprising 10-12 European nations that could command a combined force of up to 100,000 standing troops, headed by the European Commission.

The idea of a European standing force is nothing new. Europeans have debated the idea of something resembling an EU army for years, with varying results. While there are procedures in place that allow the EU to deploy NATO assets, the idea of a full EU command has always been difficult to agree on among the EU member states. While most EU states are NATO members, some, such as Ireland and Malta, are officially neutral.

“[Then-German Chancellor] Angela Merkel proposed the idea of a European Security Council back in 2015,” a former NATO official, speaking on the condition of anonymity, told me this week. “The problem was, while bigger countries like France (and previously the U.K.) loved the idea, small and medium countries didn’t like the idea of the EU’s ‘big boys’ having more say over their national security and replicating what already existed through NATO.”

The former official noted that a number of frontier states that shared borders with Russia were uncomfortable with an initiative that would give Germany a major say over their ability to protect themselves from Kremlin aggression, given Germany’s dependence at the time on cheap Russian gas.

European countries have also previously balked at the idea of the European Commission having a leading role in any kind of command structure. Any official role for the commission immediately raises the question about how the body, which is not directly elected by voters but instead has commissioners appointed by member states and the European Parliament, can represent all of the EU’s 27 member states on matters of security and defense, given the vast range of views inside the bloc itself. For example, even among the Russia hawks, Poland is unwilling to send peacekeeping troops to Ukraine, while France has already committed to doing so in the event of a peace deal. That picture gets even murkier when you look at countries friendlier to Russia, such as Hungary and Slovakia.

But 2026 has already altered the calculations. “There is a window in which this could actually happen,” a European security source said. Unlike previous efforts, “this wouldn’t be a bespoke EU structure, as Kubilius has already said it would include the U.K.,” which, given it is one of the continent’s only two independent nuclear powers, would be “essential for a European-led Security Council to work.”

Sources around Kubilius indicated that while the comments do not represent an official change in EU policy, it is broadly accepted in Brussels that thinking on European security—including the EU’s role in any future structures—needs to change and that EU institutions may need to take a back seat in order to bring parties on board.

In the past few weeks, there has been plenty of evidence that European countries—including NATO members—are increasingly willing to put themselves in direct opposition to the Trump administration.

The leaders of six European nations—Britain, France, Germany, Italy, Poland, and Spain—put their names to a joint statement with Denmark, saying that “Greenland belongs to its people, and only Denmark and Greenland can decide on matters concerning their relations.”

In ordinary times, this would be a banal statement. But it comes after repeated threats of invasion of the Danish territory from the White House, and these same countries, along with other NATO members, have also sent troops to Greenland as part of a reconnaissance mission.

While the official reason for the mission is, according to Germany, “to explore options for ensuring security in light of Russian and Chinese threats in the Arctic,” the true audience is clearly in Washington.

Europe’s comforting delusions—that Putin isn’t that great a threat, that the Americans will always be there—have been starkly exposed as false. Urgent work is needed to provide a credible European alternative to security through a U.S.-led NATO.

Yet the rigid structures of the EU can probably not accommodate the flexibility and membership required. A European Security Council would likely require something completely new, something that is not bound by any existing treaty and does not build on existing structures, such as the Berlin Plus agreement between the EU and NATO, that still involve the United States and would provide feet-draggers with vetoes. Structures that bring together like-minded countries without treaties already exist—the G-7 and the European Political Community, to name two. These could provide a good starting point for any new European security structure based on mutual political consent.

It can at times seem surreal to see proposals such as these written down on paper. But in 2026, Trump has turned the United States from an already unpredictable ally to a potential hostile state that could threaten the future of NATO. Europe simply doesn’t have the time to navigate the complicated political structures of old institutions that operated on assumptions that no longer apply. As a senior Europe security source put it, when asked about Kubilius’s comments: “We live in a new reality. We need to change our mentality, too.”