The recent public confrontation between U.S. President Donald Trump and Ukrainian President Volodymyr Zelenskyy in the Oval Office was more than just a tense diplomatic exchange; it was a watershed moment for the global order. As Trump berated and humiliated a wartime leader fighting for his nation’s survival, Europe—and indeed the world—was left to wonder: Is the United States still the "leader" of the free world, or has it abandoned that role?

For decades, American global leadership has been built on a foundation of military and economic might, as well as a commitment to democratic values and alliances. The post-World War II order, solidified through NATO and institutions like the United Nations, positioned the U.S. as the ultimate guarantor of Western security. However, under Trump’s presidency, a stark shift has occurred—one that prioritizes transactional relationships over strategic alliances and favors isolationism over international stability.

The Oval Office clash with Zelenskyy put this shift into sharp relief. Trump’s dismissive attitude toward Ukraine’s struggle against Russian aggression and his overt pressure on Zelenskyy to accept peace on Moscow’s terms signaled a dangerous pivot. The U.S. is no longer acting as the unwavering backer of democracy in the face of authoritarian expansionism. Instead, Trump’s rhetoric suggests a willingness to broker a deal that would reward Russian President Vladimir Putin’s aggression rather than deter it.

This change is sending shockwaves across Europe. Leaders like French President Emmanuel Macron and German Chancellor-in-waiting Friedrich Merz have been quick to defend Zelenskyy, making it clear that they see Russia as the aggressor. European Union foreign policy chief Kaja Kallas went even further, declaring that “the free world needs a new leader.” These words are telling. If America is abdicating its role, Europe must decide whether it can step into the void.

The continent faces significant hurdles in forging a united front. While the EU has strengthened its defense cooperation in recent years, it remains deeply reliant on American military support. NATO, the backbone of European security, is still dominated by U.S. capabilities. Even the largest European economies, France and Germany, have struggled to build a credible, independent defense infrastructure. The harsh reality is that Europe may not be prepared to stand up to Russia without Washington’s backing.

Trump’s posture toward Ukraine also raises the question of what his second term might mean for other U.S. alliances. If Trump is willing to undercut Ukraine, what does that say about Washington’s commitment to defending NATO members in Eastern Europe? Could we see a scenario where the U.S. refuses to intervene if, for instance, Russia pressures the Baltics? The chilling possibility of a divided and weakened NATO looms over this moment.

At the emergency summit in London, European leaders must confront this reality head-on. Keir Starmer, Britain’s new prime minister, has tried to position himself as a bridge between the U.S. and Europe, but that role has become more complicated as Trump drifts further from traditional Western unity. If the U.S. is no longer a reliable security partner, Europe must start planning for a future in which it takes full responsibility for its own defense and geopolitical strategy.

Ultimately, the meeting between Trump and Zelenskyy was not just a diplomatic spat—it was a warning. If America is no longer willing to lead the free world, Europe must decide whether it is ready and able to step into that role. Otherwise, the future of the democratic order could be left at the mercy of autocrats willing to fill the vacuum.