Rebuilding Europe’s Security Architecture

With Trump back, Europe scrambles to rebuild its security order—but it has agency to mend its vulnerabilities.

At a time when a single day or week can alter the course of history, political instinct, courage and timely action become indispensable. Liberal Europe now faces exactly such a turning point.

Long before Russia’s illegal annexation of Crimea and its ongoing war of aggression in Ukraine, successive US administrations had cautioned Europeans against complacency. These warnings highlighted both the shifting security landscape in Europe and a recalibration of US strategic priorities. While largely ignored by many, they resonated deeply in European nations most directly threatened by Russia’s neo-imperialist ambitions.

With Donald Trump’s return to the White House, Europeans must urgently adapt to a fundamental shift in American foreign and security policy. Europe faces nothing less than the necessity to rebuild its continent’s political and security architecture.

The pivot in US policy—both domestic and foreign—carries sweeping consequences for Europe. Foremost among these is security, as Europeans are left increasingly vulnerable. Second, the political future of Europe itself is at stake, with EU and non-EU countries forced into making profound decisions about collective goods. Third, Europe’s economic strength is under threat, as the global order that previously favoured European prosperity is rapidly dismantling. Fourth, Europe’s liberal democracies face unprecedented challenges. Finally, the manner in which Europeans interact with the United States and the wider world is undergoing significant transformation.

The most pressing challenge is clear: Europeans must now build from their own resources the capability to guarantee their security. Meeting this challenge requires genuine sacrifice, involving significant financial, military and political commitments, as well as ground-breaking efforts to reconstruct Europe’s political and security institutions. This inevitably demands reconsidering Europe’s role within NATO. However, Europeans must also confront the possibility that NATO might no longer offer an adequate security umbrella, given clear signals of US disinterest that might well turn into hostility against key European interests.

While Europe’s vulnerabilities have been exposed, the continent has also demonstrated decisive agency. In recent weeks, EU and non-EU states alike have begun to coordinate in response to the dramatic shift in US policy.

For now, NATO provides Europe’s overarching security framework, yet the continent’s political centre of gravity is already visibly shifting. This was evident recently when NATO Secretary General Mark Rutte met President Trump at the White House, while simultaneously, defence ministers from the emerging “E5” group—France, Germany, Italy, Poland and the United Kingdom—gathered in Paris to coordinate Europe’s response to Washington’s shift. The meeting in Paris felt notably more consequential than the one in Washington. Fundamentally, the profound erosion of mutual trust between Europe and the Trump administration has undermined effective cooperation within NATO.

Notably, Friedrich Merz, likely Germany’s next Chancellor, openly questioned NATO’s future on election night. He has since repeated this concern and acted decisively by initiating coalition talks with the Social Democratic Party (SPD), and both parties jointly pushed for reforms to Germany’s constitutional debt brake, exempting defence investments and launching a significant national investment programme.

Even as coalition negotiations continue, this emergent CDU/CSU-SPD coalition has worked diligently to secure the necessary parliamentary majorities to amend the Constitution—well before the Bundestag votes on Germany’s next Chancellor. This represents a profound shift in Germany’s policy, a necessary reaction to the collapse of transatlantic cooperation and the existential threat to European security posed by Russia.

Currently, considerable attention is given to Europe’s future security order. However, it would be dangerously mistaken to assume that Europe’s political cohesion will remain unaffected. These developments threaten the European Union itself. Left unchecked, the EU risks unravelling from within—a scenario eagerly anticipated by right-wing nationalists within Europe and beyond.

Internal divisions within the EU, already significant, are now being further fuelled from across the Atlantic, striking at the very core of Europe’s liberal democracies. Hungary’s government has already sided openly with the United States, recently using its veto at a critical juncture for Ukraine, resisting not only Russian military pressure but also American diplomatic pressure.

At this critical juncture, the role and influence of non-EU countries, especially the United Kingdom, have become crucial for European security, given Britain’s considerable capabilities. Yet the EU nations supporting an emerging coalition of the willing must also protect their Union from threats within.

By necessity, the emerging “E5 Plus” coalition must operate outside EU structures, due to Britain’s firm stance against any scenario resembling re-entry into the Union. Nonetheless, EU countries joining this coalition—and distancing themselves from members actively undermining European solidarity—have a vested interest in safeguarding the EU’s fundamental principles. Ideally, this process should follow the model of a “supra-governmental avant-garde,” enabling cooperating states to extend their collaboration beyond the EU treaty framework, but in accordance with transparent, predefined principles. These should include commitments to uphold and promote the EU’s supranational character. Crucially, such a grouping should function less as an intergovernmental body and more as a replica of the EU, with binding rules and active roles for EU institutions.

Integrating key non-EU countries such as the UK, Norway, and potentially Turkey will be complex, posing significant political, legal, and institutional challenges. This effort demands swift and meticulous architectural planning and active governance. Without careful management, there remains a serious risk that the EU itself could become collateral damage.

This is a joint column with IPS Journal