French President Francois Hollande on Thursday declared the security of French Jews to be a "national cause" and pledged "unrelenting combat" against anti-Semitism, including on social networks.
Hollande made the remarks in the presence of Israeli Prime Minister Benjamin Netanyahu, during a ceremony in the city of Toulouse to commemorate three Jewish children and a rabbi shot dead by an Islamist gunman in March.
"French Jews must know that the republic will do everything to protect them," he said.
Hollande also promised full transparency on what he called intelligence "deficiencies" in the case of Mohamed Merah, who shot dead seven people in total before being killed by police in a raid.
The leaders' joint visit to Ohr Torah school, where an Islamist gunman shot dead a rabbi, his two sons and the principal's daughter, was hailed by the Jewish community as sending a strong message of French determination to fight the threat to Jews from radical Islamists.
Netanyahu praised the "determined" stance of the Socialist leader, whom he called a "friend."
The Israeli premier, who is gearing up for elections in January, also used the platform to send a thinly veiled warning to Iran. Every generation brings someone "who wants to destroy us," he said.
But the Jewish people now had their own state, their own army and the means to defend themselves against those "who want to wipe us off the map," he said, leading the service in chants of "The people of Israel live."
Merah's attack and a September grenade attack on a kosher grocery store in Paris have sparked fears that groups of homegrown Islamist radicals have Jews in their sights.
Samuel Sandler, father of Gabriel Sandler, the rabbi shot dead by Merah along with his two sons, drew a line between the attack and the deportation of Jewish children from France during World War II.
"I thought that in the 21st century in France it was unthinkable to kill children, Jewish children," he said.
School principal Yaacov Monsonego, whose eight-year-old daughter was killed, said he was haunted by the image of that "black Monday" when he "let go little Myriam's hand and two minutes later she was coldly executed, simply because she was Jewish."
The ceremony was the climax of Netanyahu's two-day visit to France, which was aimed at cementing ties with the country's new Socialist leadership.
Netanyahu began his visit to Paris on Wednesday, praising French pressure on Iran and calling for "even tougher sanctions."
"The sanctions are taking a bite out of Iran's economy ... unfortunately they have not stopped the Iranian program," he said.
Israel has been an outspoken critic of Iran's suspect nuclear program, repeatedly saying that Tehran is well on the way to developing an atomic bomb.
"Given the history of the Jewish people, I would not sit by and write off a threat by those who say they are going to annihilate us," he told reporters. He said Arab nations, too, would be "relieved" if Iran were militarily prevented from obtaining nuclear arms.
Hollande has supported a push for tougher EU sanctions on Iran but wants to keep the door open to dialogue, and opposed Netanyahu's talk of possible military action.
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