In the early 19th century, when Lamartine and Chateaubriand were in their prime, Turkey was known as “the sick man of Europe.”Two centuries later, it is fast becoming the man making Europe sick—and not just Europe, but the wider Mediterranean and Near East as well.The symptoms of the new sickness are well known: the bloody invasion of Syrian Kurdistan; the suppression in western Libya of any pretense of democracy; the confrontation with Cyprus and now with Greece off the coast of Kastellorizo; the episode of the French frigate targeted on June 12 off the coast of Tripoli; the proxy war being waged through Azerbaijan with the tiny republic of Armenia; and Erdogan’s recent comments to Turkish lawmakers that “Jerusalem is our city.”Its origins, too, are clear enough: Two years ago, an entire section of The Empire and the Five Kings was devoted to it: the revival of the Ottoman paradigm amid nostalgia for the time when the Sublime Porte reigned over the homelands of Jesus Christ and Socrates; the merger of this imperial project with radical Islam—Muslim Brotherhood-style—with Ankara as its Mecca; not to mention the singular personality (all right, the disturbed personality ...) of the man who, until further notice, embodies this explosive combination.So, the real question is no longer one of diagnostics but rather of the remedies available to the West to contain the threat.We see three, in the short and medium terms:1. Turkey is a member of NATO. In fact, it has been since 1952. And we are aware that the NATO treaty contains no provision for ejecting a member. But is that a reason to passively accept proximity with a regime that, in Kurdistan, is slaughtering our most reliable allies in the fight against ISIS? Are we not obligated at least to ponder the question of the double game being played by a country that acquires F-16 fighters from the United States and S-400 antiaircraft missile systems from Russia? And is there any merit left to the old argument that we must avoid pushing that country into Putin’s arms when we can see very well that its gestures of friendship are proliferating not only with Putin but also with NATO’s rival, the Shanghai Cooperation Organisation (SCO)?Turkey must be suspended from NATO. At a bare minimum, it must be sternly reminded of Articles 1 and 2 of the treaty, which commit members to “settle any international dispute in which they may be involved by peaceful means.”2. Today’s bellicose and authoritarian Turkey has another heavy hitting ally that finances its provocations and comes to its rescue, as when, in the summer of 2018, Erdogan took the American pastor Andrew Brunson hostage and the resulting American sanctions threatened to sink the Turkish currency. That ally is Qatar. And, ironically, the very same American administration that imposed those sanctions has recently announced, through the deputy assistant secretary of state for Arabian Gulf affairs, that it will offer Qatar the coveted status of a “major non-NATO ally …” Remember, that status confers favored access to the Pentagon’s military equipment and the technologies that go with it. And remember, benefiting from this status at present are countries such as Israel, Australia, Japan, South Korea, Taiwan, New Zealand, and Ukraine. Does a microstate that spends so freely, in collusion with Ankara, to destabilize Egypt, torpedo the peace accord between Abu Dhabi and Jerusalem, and support the war efforts of Hamas and Hezbollah deserve a place in that club? When you realize the role that Qatar has never ceased to play, even as it hosts one of the region’s biggest American military bases, in evading international sanctions against Iran, is it not insanely imprudent to conclude with it an alliance that will certainly be abused if relations with Turkey take a decided turn for the worse? And how couldn’t we hope, however hopelessly, that the last few responsible minds in Washington will delay a decision that, made hastily and with no strings attached, can only give wings to the Ottoman dictator who shares with Putin the infamous honor of being public enemy No. 1 of the democracies?A message to the next president of the United States: If you want to contain Turkey, run away from Qatar.3. And then there is the question of membership in the European Union. One hears little about this. We are not even sure if the issue is present in the minds of European leaders. But the membership process, begun in 2005, remains in motion. Sixteen chapters of a negotiation that consists, statutorily, of 32, have been opened and, with one exception, remain open. Functionaries are functioning. An “association council” met again in 2019. And, putting aside the €3 billion in subsidies extorted from the union through a shameful blackmail involving migrants, Ankara receives hundreds of millions of euros in aid, each year, as part of this unstopped membership process. One might say that no one in Europe really believes in that process and that it is just one of the aberrations, or perhaps the inertias, for which the EU bureaucracy has a real knack. Maybe. But the same cannot be said for Turkey. And, for anyone who goes to the trouble to read a map of the world through the eyes of the pan-Turkic, neo-Hittite, and neo-Byzantine ideologues who give this neo-Ottoman project its intellectual framework and who, as in the time of Suleiman the Magnificent, Mehmed the Conqueror, or Enver Pasha, view Europe as a land of conquest, the matter has an entirely different symbolic meaning. We cannot comprehend why we are offering Ankara the gift of that symbol. It would be suicide to keep on allowing its wolves to get a foot in the open door of the union, the better to tear it to pieces.A door must be open or shut, Churchill told İsmet İnönü in January 1943. Between the values of Europe and the Nonaggression Pact he had signed with the Nazis two years earlier, the Turkish president was ordered to choose. And that is how we should be talking to Erdogan today. That is how to keep him at bay. And that is another aspect of the “Break with Erdogan” campaign that we will take on starting today.Kaplan and Lévy are co-founders of the nonprofit organization Justice for Kurds.