The victory of Alexis Tsipras in Greece is not terribly surprising. (The author’s play, Hôtel Europe, suggested a similar scenario.) But in the days since his Syriza party triumphed in parliamentary elections, that victory has posed a series of new political questions that, if they are to be successfully confronted, will require all the composure that Europe’s leaders, especially French President François Hollande, can muster.

1. Whatever the demagogues say, Greece was on the path to recovery. It was a fragile recovery, to be sure. One that cost the Greek people a nearly intolerable amount of pain and suffering. But it was a recovery all the same, one that showed a modest return to growth, productivity gains, and a crack in the ice on the job front—all of which would be reduced to nothing by the demagogic measures (such as a moratorium on privatization and a freezing of foreign investments) that had been served up to Syriza voters.

So what will it be, information or intoxication? What are we to make of the practitioners of magical thinking who see in the “banksters” of “the Troika” the source of all their woes, or of the new minister of finance, the moderate Yanis Vafourakis, explaining the need for a clean break with the curse of Sisyphus endlessly rolling his deficit rock up the hill?

2. Despite the claims of the proponents of the new socialism for dummies that Germanophobia has become, Germany had begun to hear those who have been arguing against unlimited austerity of the kind in which the remedies are tantamount to drinking hemlock. Since last week, however, Germanophobia is back. The scapegoating of Angela Merkel has come back with a vengeance in the Greek press. Another few weeks of this and the Greeks will forget that it was not Mrs. Merkel but bloated bureaucracy, corruption, and bad governance among Greek elites and, often enough, alas, members of the middle class, that nearly ruined Greece and that, in fact, will ruin it if structural reforms too long deferred are not pursued without further delay.

3. The euro may explode. And the One of the single currency may, to paraphrase the famous dialectic, quickly divide into Two. This is something I have feared for years. It is the nightmare scenario that occurs sooner or later when a currency’s introduction is not followed by harmonization of the tax, tariff, and monetary policies of the members.

If Greece defaults or, without actually defaulting, pulls too hard on the chain of its debt and demands rescheduled payments and interest-rate concessions that are experienced by citizens of neighboring countries as imposing an intolerable increase in the burden of their own debt, or, what amounts to the same thing, as an unfair mortgaging of their future—in that case, then, the European Union will find itself in the situation of two previous failed monetary unions, the Scandinavian (1873-1914) and the Latin (1865-1927) the undoing of which began with troubles in … Greece!

4. The alliance of the extreme left and the extreme right is a specter that has stalked Europe for nearly 40 years. That specter took a trial lap around the intellectual track in France in the 1970s and a second, in Berlin, 10 years later. I can still hear Ignatz Bubis, then leader of Germany’s Jewish communities, expressing his alarm at the collusion of radicals on both sides in the “affair” set off when leftist writer Martin Walser declared that he was fed up with “Holocaust blackmail.” Then yet another trial lap in Russia, where a “national Bolshevik” party, founded by writer Edward Limonov in the purist tradition of the “beefsteak sections” (red inside, brown outside) of the 1930s, provided the inspiration for the Eurasianism of Vladimir Putin and his ideologist, Alexander Dugin.

That same alliance finally receives its letters patent of nobility when, in Athens, the cradle of democracy, the Greek far left forms a coalition with ANEL, a party as overtly nativist and racist as that of France’s Marine Le Pen. What is the future of this collusion? What will be the consequences, in France, for example, where Le Pen, the leader of the National Front, saluted “the giant democratic slap that the Greek people have just given to the European Union”? Time will tell. But it is a collusion that must be kept at bay.

5. Putin, again. Russia’s ambassador was the first to congratulate Tsipras. We know that Syriza has repeatedly reaffirmed its cultural and political solidarity with Russia. And we heard Greece’s new minister of energy, Panagiotis Lafazanis, declaiming moments after his appointment his opposition to the “embargo [sic] imposed on Russia.”

How is one to interpret these signs? Should we conclude that the closeness with Russia may eventually result in an alternative alliance for Greece ? And is it imaginable that Vladimir Putin has found, in the person of Alexis Tsipras, a Trojan horse in the war of attrition that he appears to have launched against the European Union and its values?

I shudder to think. But there is a simple way to find out. Days ago, George Soros and I appealed to the Council of Europe to grant Ukraine exceptional access to the balance-of-payments support fund designed for European states that are not members of the euro zone. Because bending the rule will require not just a majority of the Council but unanimous agreement, I suggest that Mr. Tsipras be asked forthwith whether or not he favors this gesture of support for Ukraine. Or will we witness from him, when the time for a vote arrives, a diehard bellicosity plainly intended to force Petro Poroshenko to bow down to the master of the Kremlin?

That would be a test of the truth.

Translated from the French by Steven Kennedy.