THERE ARE times—and the present moment is very much one of them—when certain great poems, minatory and ominous, force their way into the mind. It might be Cavafy’s “Waiting for the Barbarians,” or Auden’s “The Fall of Rome,” not to mention Kipling’s “Recessional” and “The White Man’s Burden.” Published in 1898, the latter’s subtitle, more interesting than its lurid title, is “The United States and The Philippine Islands,” but might just as well be “The United States and the Middle East” more than a century later, with its warning about “The blame of those ye better, The hate of those ye guard.”

And of course, “The Second Coming.” In that extraordinary, oracular work, W.B. Yeats was not making a trite political statement. Although the lines

“Mere anarchy is loosed upon the world, The blood-dimmed tide is loosed, and everywhere The ceremony of innocence is drowned;”

were in part inspired by Ireland, where a brutal terrorist campaign was being waged (dignified as a “War of Independence”), about which Yeats, the sentimental nationalist who also identified with the Protestant Ascendancy, had such mixed feelings, they were not meant to be a guide to everyday politics. Yet the words “the centre cannot hold” and “The best lack all conviction, while the worst / Are full of passionate intensity,” written in 1919, seemed all the more forceful with every year over the next decades of totalitarianism, total war and total murder. So they do again today.

We have witnessed the explosion of the Levant and the implosion of Europe, the rise of demagogues on both the Left and, more notably, on the Right, on both sides of the Atlantic. The internal atrophy of democratic politics in the United States is another question, although one that Americans appear reluctant to address. Anyone can deride Donald Trump’s vulgarity, but those who do so are less inclined to ask what possible reason there is why Hillary Clinton should be president, or whether the Americans can really lecture benighted Mahometan savages about the benefits of democracy when little more than one American citizen in three bothered to vote at the last midterm elections in 2014 (one in five in Mississippi and Utah). And in any case, whoever votes, the United States is blessed, as Mark Twain was the first to observe, with the best Congress money can buy.

BUT WE Europeans should hesitate before sneering in turn. Constitutional representative government is always a fragile plant, which needs to be carefully tended and nurtured, and doesn’t always flourish of its own accord. What has happened in these recent years is not just the near collapse of the European Union, but the demonstration of its complete inadequacy to deal with present dangers, from the self-inflicted and unresolvable crisis of a single currency which was never what English law calls “fit for purpose,” to the awful problem of mass immigration from mostly Muslim countries in western Asia and north Africa—a problem both for Europe and for the countries the migrants leave.

Beyond that is the acute threat within Europe to political stability. That stability was based on an unwritten agreement, what was sometimes a far too cozy and smug consensus between ostensibly moderate parties, “center-right” and “center-left.” It’s this consensus that is now being severely challenged from the outside left and outside right by parties and politicians called “extremist” or, much more revealingly, “populist.”

This is true in the Eastern European countries that have only been free of dictatorship and Soviet imperialism for a quarter-century, and have belonged to the European Union for little more than ten years. They have shown alarming signs of sliding back into authoritarianism, nativism, racism and corruption. But then maybe the hopes held for their immediate evolution into a liberal democracy most of them had never known was always illusory, particularly in Hungary and Poland, the latter of which appears to ape the former as it conducts what amounts to a Gleichschaltung of its state institutions.

More perturbing are events in the Western European countries that created the new Europe, the original six which signed the Treaty of Paris in 1951 (creating the European Coal and Steel Community), and then the Treaty of Rome in 1957 (creating the Common Market or European Economic Community). The three largest of these countries were France, Germany and Italy. Their recent experience is somber.

IN FRANCE, the old liberal consensus is threatened principally by the Front National. Its origins are dark, and merited the label “neofascist” when its leader Jean-Marie Le Pen (suspected of torture and murder when he was a French soldier in the squalid Algerian war) used blatantly racist and anti-Semitic rhetoric. His daughter Marine is much cleverer and better attuned to the public mood than her father. She has tried to pursue “de-demonisation,” to the point of expelling her own father from the party, but the anti-immigrant, anti-Muslim tone persists.

Fourteen years ago, the French establishment had a nasty shock when Le Pen père ran second in the first round of the 2002 presidential election, knocking out the Socialist Lionel Jospin and forcing the Socialists to support the conservative Jacques Chirac in the run-off lest Le Pen win. “Add to that,” writes Natalie Nougayrède in the Guardian, the nearly seven million votes the Front National won in the regional elections last December, “and it becomes obvious that dark clouds have also gathered.” It’s by no means fanciful to suppose that the daughter could also run second in 2017’s presidential election—or even win. What would be the consequences for relations with Germany? The Franco-German alliance welded together by Charles De Gaulle and Konrad Adenauer was at the core of the idea of European unity, two foes whose enmities had repeatedly enmeshed Europe in strife now making common cause both militarily and politically.

A different kind of repudiation of established politics has been seen in Italy. Three years ago, the moderate socialist Democratic Party and the absurdly named “People of Freedom” party, led by the mountebank Silvio Berlusconi, each touched 30 percent of the vote, but were both astonished by the Five Star Movement close behind them, led appropriately by a comedian, Beppe Grillo (a comic by profession, that is, rather than an unwitting buffoon like Berlusconi). This is the very type of new “pop-up party,” comparable to but more successful than, the German “Pirates.” The Cinque Stelle is not discernibly Left or Right but just anti: antiestablishment, antiausterity, anti-European. It could be called antipolitical, and almost anti-Italian. Such random protest parties are often labeled Euroskeptic, but although the graffito slogan you can see in the Veneto, “Basta Italia!,” will probably be painted by a supporter of the rightist Northern League, that’s the spirit of Grillo’s Five Stars as well: enough Italy as well as enough Europe, enough of our rulers, throw the rascals out. This is the specter haunting those rascals, or at any rate what that interestingly heterodox French politician Jean-Pierre Chevènement calls “the soi-disant elites.”

IF THE ECLIPSE of the official centrist consensus causes puzzlement as well as widespread dismay, its origins take less explaining. When the European democracies were reborn—or reinvented—after 1945, there was a crystal-clear mission, not only to be peaceable and constitutional, but also to thwart extreme politics on either side. Among other legacies, the French Revolution bequeathed to us the potent and beguiling—but often misleading—political metaphor of Left and Right, from when the meeting of the National Assembly the radical bourgeois took their seats to the left of the conservative aristos. This image has always had limited application, and maybe very little in American politics, with its sundry peculiar institutions. If we still do use that metaphor, every important conservative party in Western Europe today stands to the left of the Democrats. But were the Democrats ever a left-wing party in the European sense? In its Rooseveltian heyday the Democrats were a truly weird alliance of organized labor, city bosses, intellectual liberals, the ethnic urban working class and Southern segregationists.

By midcentury, American politics had a Tweedledum and Tweedledee aspect, so that it was hard to distinguish the parties. Dwight Eisenhower was nominated by the Republicans and elected president in 1952, but he might just as well have been nominated by the Democrats. It wasn’t until the conservative movement rose up and conquered the GOP that a truly vivid distinction could be made between the two parties.

In Europe, the journey has if anything been in the opposite direction over the second half of the last century. Conservative parties moved towards the center from the right as socialist parties did from the left. This was a reaction to the events of the first half of the century, when polarization between Left and Right had had such catastrophic consequences. Modern European democracy was a repudiation of all species of totalitarianism, nurtured by two traditions in harness, Christian Democracy and Social Democracy. They both altered their positions or tone after the horrors between 1914 and 1945 that shouldered Right and Left with so much historical baggage to shed, in the form of fascism and Communism.