The slayings at a Jewish school at Toulouse are a moment not only of horror for France and the world but also of truth. They will remind that before the government of the Fifth Republic has any standing to lecture the government in Jerusalem on how to protect Jews in the land of Israel, it will have to show that it can protect the Jews of France. The killings in the southern French city are being attributed by police to a gunman who shot to death a 30-year-old Hebrew teacher and his two children and another child and wounded a 17-year-old. “The attacker was shooting people outside the school, then pursued children into the school, before fleeing on a heavy motorbike,” the prosecutor at Toulouse, Michel Valet, is quoted by Reuters as having told reporters.

Authorities are scrambling to see whether the heavy-caliber firearm and another weapon used by the killer were also used in the killing of three soldiers in two separate shootings last week by a man who escaped on a scooter. It’s too soon to say what they will find about the killings, but it’s not too soon to say that an attack on a Jewish school is cause for the highest possible alarm, particularly in France. No doubt this is why President Sarkozy, along with a raft of other high-ranking French officials, was, at this writing, racing to the scene. “I want to say to all the leaders of the Jewish community, how close we feel to them,” the president said. “All of France is by their side.”

No doubt Mr. Sarkozy understands the implications for the credibility of his government, not only at home, where he is locked in an election campaign, but internationally, where he seeks to be a player in, among other theaters, the Middle East. Shortly before he acceded to the presidency, he came to New York, where, at a small lunch, he was asked point blank by the editor of the Sun whether he thought his government would be able to protect the Jews of France. “C’est une question tres grave,” he said, before assuring that it would be able to defend the Jews and asserting that the French people are broadly and deeply opposed to anti-Semitism. Today his remarks in respect of solidarity with the Jewish community were echoed by the socialist candidate, Francois Hollande, and the right wing candidate, Martine LePen.

There’s a reason that the question of anti-Semitism keeps arising in France, and it’s not just because of the nature of the incidents — physical attacks, defiling of graves, and harassing of Jews in religious garb — that occur all too frequently. It’s also because of the foreign policy of France. This point was noted in these columns in 2005, after Commentary magazine issued a special report on Jews, Arabs, and French diplomacy. At the Quai D’Orsay, the writer for Commentary, David Pryce-Jones, reported, “The historical record displays evidence of unremitting hostility to Jews, decade after decade.” The Quai D’Orsay took great umbrage at the piece, but we said at the time that New Yorkers were a hard-headed lot and knew whom to credit.

We also made the point in 2004, when Prime Minister Sharon issued a blunt warning for Jews to flee France in the face of escalating anti-Semitic attacks there. In the weeks before Mr. Sharon issued his broadside, vandals had destroyed a mural painted by Jewish schoolchildren, a 17-year-old Jewish student had been stabbed in the neck in a Paris suburb, a town hall in Vichy had been painted in swastikas, the slogan “Jews out” had been painted on graves at Colmar, a Jewish center had been set on fire at Toulon, and a school for Jewish boys had been firebombed. A stain was spreading on the Fifth Republic. Yet, we noted, even that kind of violence wouldn’t, in and of itself, lead a prime minister of Israel to urge the Jews to flee.

Most worrisome, we noted, was that the eruption of violence against Jews in France has coincided with the endorsement by the Quai d’Orsay of the Palestinian right to take violent action against Jews in Israel and the embrace of the Palestinian Arab terrorist leadership by the president at the time, Jacques Chirac, and other French officials. Mr. Chirac had recently stood with Egypt’s president at the time, Hosni Mubarak, and endorsed the authority of Yasser Arafat. It turned out that even while the Quai D’Orsay was opposing America’s efforts to remove Saddam Hussein’s regime at Iraq, even while Iraq was funding the families of suicide bombers who’d attacked Israel, even while a diplomat of France was telling the British that Israel was a “s**tty little country,” a number of officials in France were among those receiving oil vouchers from Saddam.

We don’t mind saying that President Sarkozy is a lot better than President Chirac was. But no leader of France in our time has emerged as fully on the side of the Jews in the war that is being levied against them across a broad swath of the globe. We have noted in the past, and note again, that France isn’t pre-war Germany. We haven’t suggested, and don’t do so now, that the government or its leaders are anti-Semitic. But we do suggest it doesn’t matter. If France is going to defend its Jews, it is going to have to defend, as well, the Jews of other countries, including Israel. That is the real lesson of the long, tragic story of the violence that has erupted against the Jews of France.