What Trump has done is to divide and alienate potential allies—and push his opponents to embrace the silliest extremes of the #WelcomeRefugees point of view. By issuing his order on Holocaust Remembrance Day, Trump empowered his opponents to annex the victims of Nazi crimes to their own purposes.

The Western world desperately needs a more hardheaded approach to the issue of refugees. It is bound by laws and treaties written after World War II that have been rendered utterly irrelevant by a planet on the move. Tens of millions of people seek to exit the troubled regions of Central America, the Middle East, West Africa, and South Asia for better opportunities in Europe and North America. The relatively small portion of that number who have reached the rich North since 2013 have already up-ended the politics of the United States, the United Kingdom, and the European Union. German chancellor Angela Merkel’s August 2015 order to fling open Germany’s doors is the proximate cause of the de-democratization of Poland since September 2015, of the rise of Marine LePen in France, of the surge in support for Geert Wilders in the Netherlands, and—I would argue—of Britain’s vote to depart the European Union. The surge of border crossers from Central America into the United States in 2014, and Barack Obama’s executive amnesties, likewise strengthened Donald Trump.

It’s understandable why people in the poor world would seek to relocate. It’s predictable that people in the destination nations would resist. Interpreting these indelible conflicts through the absurdly inapt analogy of German and Austrian Jews literally fleeing for their lives will lead to systematically erroneous conclusions.

We need a new paradigm for a new time. The social trust and social cohesion that characterize an advanced society like the United States are slowly built and vulnerable to erosion. They are eroding. Trump is more the symptom of that erosion than the cause.

Trump’s executive order has unleashed chaos, harmed lawful U.S. residents, and alienated potential friends in the Islamic world. Yet without the dreamy liberal refusal to recognize the reality of nationhood, the meaning of citizenship, and the differences between cultures, Trump would never have gained the power to issue that order.

Liberalism and nationhood grew up together in the 19th century, mutually dependent. In the 21st century, they have grown apart—or more exactly, liberalism has recoiled from nationhood. The result has not been to abolish nationality, but to discredit liberalism.

When liberals insist that only fascists will defend borders, then voters will hire fascists to do the job liberals won’t do. This weekend’s shameful chapter in the history of the United States is a reproach not only to Trump, although it is that too, but to the political culture that enabled him. Angela Merkel and Donald Trump may be temperamental opposites. They are also functional allies.