By MICHAEL GERSON

BERLIN—It is strange being in a foreign country and watching American post-World War II leadership—as practiced by presidents such as Harry Truman, Dwight Eisenhower and Ronald Reagan—collapse into a heap of chaos, ignorance and self-indulgence.

Donald Trump’s performance at the G-7 in Quebec—his personal attacks on other leaders, his tariff threats against close allies, his rejection of the joint communique via Twitter—will strike most Americans as just another day at the office for the great disrupter. For Europeans, it was a demonstration that the seedy, derelict carnival of Trumpism is not just a show put on for Trump’s political base. Or more accurately: Everything Trump does is a seedy, derelict carnival put on for his political base.

What did the alternative communique consisting of Trump’s words and actions convey? That the American president has a level of open animosity toward Canada, France and Germany that is unlike anything we’ve seen in the modern era. That the American foreign-policy process doesn’t work and should be treated as a joke. That the traditional leader of the West no longer understands or accepts the concept of “the West.”

To be an American in Germany these days is to be besieged by earnest, anxious questions about the intentions of America’s president. Germany is a country—because of a unique and horrible history—that provides leadership by standing for a rules-based global order. Since power proved so dangerous, it must be replaced by process. This worldview is especially threatened by Trump’s comfort with chaos and rule by impulse.

During the first year of the Trump administration, it was possible to assure concerned foreigners that the president was being constrained by responsible advisers. He did not dissolve NATO, or abandon NAFTA, or bug out of Afghanistan. But now we are seeing Trump unbound: a president increasingly confident in his own damaged instincts, untethered from reality and surrounded by advisers chosen to amplify his insanity.

So, if encouragement is no longer possible, what about a little schadenfreude? I lived through a period in the 2000s in which Europeans (and Canadians) often complained about American exceptionalism. It was dismissed as arrogant, messianic and annoying. And, no doubt, Americans can be a bit much to take.

But is post-exceptionalism America really more desirable? The Trump administration has moved toward a more Putin-like foreign policy: oriented toward narrow economic and security interests, dismissive of human rights and humanitarian concerns and tilted toward the cultivation of favorable despots. And this shift has been matched by a changing national self-conception. With a president systematically attempting to undermine sources of authority that check his power, our nation is becoming normal in other disturbing ways. We had thought that democratic digression only happens in other places.

One effect of this shift away from idealism and universalism is the loss of certain universal ideals that helped bind the Atlantic alliance. The Atlantic Charter, authored by FDR and Winston Churchill, was not just a statement of national war aims but of international commitments—to economic collaboration, self-government and a “wider and permanent system of general security.” These vows are what turned resistance to Soviet aggression from a necessity into a cause. With these commitments, western countries were a squabbling family. Without them, they are just squabbling neighbors, throwing garbage across the fence.

This is perhaps the largest foreign policy crisis of our time: an American president who has lost the ability to distinguish friends from enemies. Our traditional friends are attacked as freeloaders and cheats. Our real enemies are praised and cultivated — in the case of Russia, allowed to undermine American elections with minimal consequence and sponsored by Trump for readmission to the G-7. Trump’s moral blindness has led to strategic turmoil.

America has had weak leaders before. But since World War II, every president has mentally located his country in the free world, bound by democratic values, trade and common purpose. Trump is operating on a different map. He is actively hostile to the internationalism that defined the western alliance. And he is joined by rising ethno-nationalist forces within Europe itself.

We don’t know how this chaos will eventually coalesce. But one thing is certain: The alternative to the free world will be less free.

(Washington Post Writers Group)