The Orlando nightclub shooter, the worst mass-casualty gunman in US history, was the son of immigrants from Afghanistan. The San Bernardino shooters were first and second generation immigrants from Pakistan. Nidal Hassan, the Fort Hood killer, was the son of Palestinian immigrants. The Tsarnaev brothers who detonated bombs at the 2013 Boston marathon held Kyrgyz nationality. The would-be 2010 Times Square car bomber was a naturalized immigrant from Pakistan. The ringleader of the Paris attacks of November 2015, about which Donald Trump spoke so much on the campaign trail, was a Belgian national of Moroccan origins. President Trump’s version of a Muslim ban would have protected the United States from none of the above.

If the goal is to exclude radical Muslims from the United States, the executive order Trump announced on Friday seems a highly ineffective way to achieve it. The Trump White House has incurred all the odium of an anti-Muslim religious test, without any attendant real-world benefit. The measure amounts to symbolic politics at its most stupid and counterproductive. Its most likely practical effect will be to aggravate the political difficulty of dealing directly and speaking without euphemisms about Islamic terrorism. As ridiculous as was the former Obama position that Islamic terrorism has nothing to do with Islam, the new Trump position that all Muslims are potential terrorists is vastly worse.

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.