Arguably, the 2012 attack that caught the Toulouse community unprepared was more traumatic because children were killed. And the 1982 attack on the Goldenberg Jewish restaurant in Paris was deadlier than last week’s attack and involved more assailants.

Yet the deadly hostage siege at Hyper Cacher, which came amid a dramatic increase in attacks on French Jews, may nonetheless be the watershed moment that changes the community’s dynamics for the foreseeable future. That’s because it compounds the problems that are already depleting the community’s ranks.

“These events are having such a profound effect because they target people who go to synagogue and eat kosher — the group that in France is simultaneously the beating heart of the community and the population likeliest to leave for Israel because of its Zionist attachment,” said Avi Zana, director of the Israel-based Ami Israel association, which facilitates aliyah from France.

France has Europe’s largest Jewish community, with anywhere from 500,000 to 600,000 members. Most live in Paris and are Sephardic, and about half belong to some Jewish social or religious framework. Community life is robust, and the country has hundreds of Jewish schools.

But a number of coinciding factors — including attacks by Islamists with combat experience gained in the Middle East, the French far right’s rising popularity, economic stagnation and an increase in taxation — is creating record levels of Jewish immigration to Israel and elsewhere.

Last year, a record number of French Jews — more than 7,000, twice as many as the previous year and three times as many as in 2012 — moved to Israel.

Before the Jan. 9 attack on Hyper Cacher, where an Islamist killed four Jews, the Jewish Agency estimated that 2015 would bring 10,000 French Jews to Israel. But the attack will require a reassessment, Jewish Agency Chairman Natan Sharansky told JTA. Moshe Sebbag, the rabbi of the Grand Synagogue of Paris, said he expected 15,000 French newcomers to Israel this year.

The rise in French aliyah — Hebrew for immigrating to Israel under its law of return for Jews — can be tied at least in part to last summer, when several French synagogues and Jewish shops were attacked during demonstrations against the Gaza war.

“We may well see 30,000 Jews from that group leave for Israel in the coming three years, and that would mean the departure of 15 to 20 percent of the affiliated community,” Zana said. “This has the potential, unfortunately, of considerably weakening some of the community’s institutions. The community needs to prepare for it.”

Daniel Benhaim, the Jewish Agency’s chief envoy to France, speaks of 50,000 Jews who are expected to move to Israel by 2024.

“In an affiliated community of 200,000, that’s already a critical mass whose departure will deeply impact the internal dynamics remaining community,” he said, referring to Jews who are somewhat observant and attend Jewish institutions.

In parallel to the increase in aliyah, there has been in recent years an increase in emigration by French Jews to Canada and the United States, Zana said.

“There are not statistics on that movement, but it is definitely significantly smaller than the movement to Israel,” he added.

Schools are a major concern pushing Jewish parents to make aliyah, according to Zana.

“On the one hand, parents increasingly are apprehensive about enrolling their children in public schools because of rampant anti-Semitism there,” he said. “On the other, they are afraid to put them in Jewish schools because they are targets for attacks. So Israel seems like a good choice.”

Yvan Lellouche, a Jewish grandfather who is seeking to make aliyah in the coming months, told JTA on Sunday that he fears for the 15 children from his extended family who attend a Jewish school near Hyper Cacher.

“Every minute they are there, I fear for their safety. I fear for my safety as well,” he said.

Speaking at the Knesset on Tuesday, Joel Mergui, president of French Jewry’s religious affairs organ, the Consistoire, said children are likewise frightened.

“It is hard to describe how afraid our children are to go to Jewish schools in France,” he said.

Some Paris Jews are feeling the aliyah-related depletion already in their own synagogues, including Bernard Mouchi, president of the Jewish community of Courneuve — an impoverished and heavily Muslim suburb of Paris.

“Fifteen years ago this was a large Jewish community of over 1,000 families,” he told JTA at his synagogue, where 30 men congregated on Saturday evening under police protection. “Now there are 100 families, and we are actually a community of pensioners.”

“Many made aliyah,” Mouchi said. “Others left for safer areas around Paris.”

In light of this phenomenon generally, Chlomik Zenouda, vice president of France’s National Bureau for Vigilance Against Anti-Semitism, said, “The community will need strong leaders who will know how to downsize the community’s institutions and basically shut it down.”

Meanwhile, the accumulation of French-speaking Jews in Israel is creating a snowball effect because it is drawing newcomers to join friends and family who left while reassuring them of a social infrastructure that would facilitate their absorption, according to Karin Amit, a researcher with the Ruppin Academic Center’s Institute for Immigration and Social Integration who has studied French aliyah.

“There seems to be a momentum for aliyah that is fueling itself in a way within the Jewish community of France,” said Amit.