RUTHFULLY YOURS

But does the fall of Raqqa really mean the fall of Islamic State? One needs merely a sharp object—or as we saw last week, a rented truck—and a nearby group of “infidels” to be an ISIS soldier.

After the Oct. 31 New York attack, Mr. Trump tweeted: “We must not allow ISIS to return, or enter, our country after defeating them in the Middle East and elsewhere. Enough!” But ISIS’ most important battlefield is not in the Levant; it is online, in hearts and minds. ISIS’ power comes from ideas, not territory.

The threat is from within as well as without. Sayfullo Saipov, the Uber driver who allegedly murdered eight in ISIS’ name, had been living an unremarkable life in the U.S. for seven years. Thousands of young Muslims have left Europe and the U.S. for Syria and Iraq to answer Mr. Baghdadi’s call. Seduced via social media, young men and women, some of them converts, are also taking up arms in the West, or leaving their homes in Chicago, London and Paris, to live, and perhaps die, for a cause.

The Obama administration argued that young people join ISIS because of poor economic prospects. “We can work with countries around the world to help improve their governance,” State Department spokeswoman Marie Harf said in 2015. “We can help them build their economies so they can have job opportunities for these people.” That’s myopic. Physicians, computer scientists and star high-school students have been radicalized, too. People are motivated by meaning more than money.

While Western states do (or used to) provide good social services, economic opportunity and consumer goods, they are increasingly indifferent to questions of meaning—to principles worth living, and perhaps dying, for. In the U.S. we are proud of our freedom—but freedom to do and care for what? For a small but not negligible number of young people, answering a call to build a caliphate, allegedly based on the dictums of a holy book, will seem a more genuine choice than ambition or consumerism.

Mr. Trump should know this. His campaign was a kind of call for meaning. Whatever the merits of Mr. Trump’s positions, he framed his views on trade, immigration and foreign policy in terms of America’s national identity: “Make America Great Again.” Hillary Clinton emphasized technical solutions. Can anyone remember her slogans, her rallying cries? There was “breaking down barriers” and “fighting for us” and “I’m with her.” None stuck. She ended on “stronger together.” Together with what or whom?

It’s not a new problem. In Germany’s Weimar era, the jurist Carl Schmitt argued that political liberalism, in deriving supreme political value from individual liberty, gave rise to a paradox he called “depoliticization.” For Schmitt, politics boiled down to disputes over fundamental principles. A state that enshrines individual freedom must allow citizens to pursue their private ideas of the good, as the state itself is barred from laying claim on transcendent values. Liberalism thereby shrinks politics to a series of technical arguments over the most efficient means for achieving material ends.

For an example of depoliticization, consider Mrs. Clinton’s “basket of deplorables” remarks. Half of Mr. Trump’s supporters, she said, “are irredeemable, but thankfully they are not America.” The other half “are people who feel that the government has let them down, the economy has let them down, nobody cares about them, nobody worries about what happens to their lives and their futures, and they’re just desperate for change.” The implication is that the only legitimate basis of political disagreement is over the means of attaining prosperity and material security. The Trump movement perceived that political differences run deeper—that they are civilizational and cultural.