Five letters grabbed the headlines over and over again in Germany this week: T-R-U-M-P.

German Chancellor Angela Merkel (C) talks to French President Emmanuel Macron as they gather with NATO member leaders to pose for a family picture before the start of their summit in Brussels, Belgium, May 25, 2017. REUTERS/Jonathan Ernst

And after spending a day in Berlin at the “T20” – an event designed to bring ideas for solutions to global problems to the G20, one overriding takeaway emerged: The American president is driving other countries to clarify their ideas about the importance of globalization and governance in ways that he likely never imagined and Washington never intended.

America may have been one of the founders of the G20, but the band sounds ready to move on without its lead vocalist – or at least to hum a different harmony while the United States sings its own tune.

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Call it the silhouette hanging over the room. Trump and his view of America first, Paris maybe not, free trade not so much hung over nearly every conversation and discussion about where the G20 is headed this year and next, and how it will proceed now that the nation that was once a central organizer is now a central organizing principle – a founding force for global cooperation and collaboration that once rallied Europe, but which now stands tall and loud in Berlin and Paris as an symbol of how not to act toward your partners. In Europe’s view United States is no longer the sun, but the shadow of global alliances.

In just about every conversation, Trump’s name was invoked, not as an example, or even as a punch line, but as the source of potential danger – a leader who doesn’t much care about rules-based order, cooperation across borders on issues such as climate change or what the idea of “global governance” means. A leader who is tossing over the apple cart of commonly accepted wisdom when it comes to America’s role in facilitating stability and prosperity worldwide.

Indeed, those who oppose Trump did not hide their feelings about what he means for this moment.

“Trump by himself makes the world dangerous, but he also represents larger U.S. forces,” said economist Jeffrey Sachs during his speech in Berlin. “Do not argue with Donald Trump about climate science; he would only enjoy it. He would look at you like you are the fool to argue with him because he doesn’t give a damn about climate science.”

Lars Hendrik-Roeller, chief economic adviser to German Chancellor Angela Merkel and a key adviser regarding Germany’s G20 presidency, was careful to not comment on American decisions regarding climate change when answering questions about whether there is a G20 or whether there is, in fact, a G19 plus one.

The trans-Atlantic relationship, so long discussed in hushed terms as central to Germany and a significant support for the European Union, now sits in the center of the ring, pummeled by an American leader not sure how much he wants to tend to it and a Europe re-thinking whether that relationship is still vital. Or at least plotting its path forward with less American support, if necessary.

For those in Germany who were already committed to rethinking the post-World War Two order, it seems America already has beaten them to it by electing a leader who is less likely to soothe European fears of a fraying friendship than stoke them.

And for those in the emerging world already tired of waiting for rich nations to remember they have a seat at the table, Trump offers an opportunity to define not just what their nations stand for – such as a commitment to combating climate change – but what they don’t.

Or as Argentine economist Beatriz Nofal noted while on stage in Berlin, it is up to Argentina, which next holds the G20 presidency, and other emerging nations to chart the way forward in the absence of U.S. leadership.

So whether intentionally or not, Trump has managed to do something rare among American presidents: unify the Europeans, galvanize the globalizers and offer future G20 leaders a chance to define themselves in contrast to an America no longer at the center of global cooperation.