It was chicken tenders night at Yale’s chapter of Hillel, the Jewish student group, and the basement dining hall was packed with boisterous, hungry students attracted by overflowing vats of kosher fried chicken and vegan mac and cheese.

Some students kissed the mezuza on the way in. Others were not even Jewish, but came for the food and companionship, a sign of the pluralism that Hillel — the dominant Jewish campus organization in the United States — says it embraces.

Yet under the surface, there were signs of strain, after months of divisive protests on campus over the war in Gaza. A silent question hung in the air, several students said: “Which side are you on?”

Few American organizations have been touched by clashes over the war quite the way Hillel has. The movement, founded in 1923 at the University of Illinois, now has chapters at 850 colleges and universities around the world, from highly selective private schools like Yale to big state universities like Texas A&M. The Hillel movement, including Hillel International and the campus Hillel chapters, had $200 million in revenue in 2023, received from tens of thousands of donors.

Hillel centers are where college students go to cement their sense of Jewish identity, or to discover it. Its slogan is “all kinds of Jewish,” and it aims to be welcoming to all.

But as the conflict in Gaza continues, some Jewish students believe that Hillel is not critical enough of the Israeli government’s conduct of the war, and too defensive in its support of Zionism, a belief in the right of Jews to a Jewish state in their ancestral land of Israel.

Hillel, for its part, is unapologetic. “Hillel as an institution has been and remains committed to the support of Israel as a Jewish and democratic state, that fulfills the right of Jewish self-determination in an ancestral homeland,” Adam Lehman, Hillel’s chief executive officer, said in an interview.

The shock of the Hamas attack of Oct. 7, 2023, against Israel has moved many Jewish students to explore what it means to be Jewish, fueling significant growth in interest in Hillel on campuses around the world. During the 2023-24 school year, as the conflict in the Middle East escalated, a record 180,000 students participated in Hillel activities at least once, 12,000 more than the year before, according to the organization. There was also an uptick in the number of “super-users,” who visited Hillel at least six times.

Over the last year and half, though, the solidarity that came with that identity has cracked.

The fissures can be felt in public life and in synagogues. And the division among Jews more generally is playing out among Jews on campus, as some complain that Hillel is too aligned with Israel, while others say that it is too open to critics of Israel.

Many students find it hard to divorce themselves from Hillel completely, especially in this time when they may not feel safe expressing their Jewish faith and identity outside their own community.

Some students, like Emanuelle Sippy, a senior at Princeton, look for a middle ground. She still goes to Hillel for prayer services, meals and lectures. But in the search for a more congenial left-wing political environment, she also helped to revive a small rival group, the Alliance of Jewish Progressives, on her campus.

“There is a group of people — very close friends, people I respect and admire — who are fighting battles within these institutions like Hillel,” she said. “They might be showing up to events. Hillel might be counting them. It doesn’t mean they don’t have criticisms.”

This is not the first time that there has been a schism among students at Hillel.

Students at Harvard launched an Open Hillel movement in 2012, in protest against the parent organization’s policy against partnering with anti-Israel groups. In December 2013, students at Swarthmore Hillel declared themselves the first “Open Hillel” chapter in the nation, vowing to promote open inquiry, regardless of ideology.

The current ideological split feels sharper, as campus protests for and against Israel have led to arrests, suspensions and lawsuits. When it comes to the campus Hillel, “a lot of students don’t feel comfortable going in for political reasons,” said Danya Dubrow-Compaine, a senior and a co-founder of Yale Jews for Ceasefire.

There is also a growing generation gap. In a Pew survey conducted in February 2024, 38 percent of adults under 30 years old said Israel’s reasons for fighting Hamas were valid, down from 41 percent two years earlier. That compares with 78 percent of people 65 and older who said the same, up several points from the earlier survey.

Elijah Bacal, a sophomore who is an organizer for Yale Jews for Ceasefire, said the institutional leadership of the Slifka Center, as Yale’s Hillel is known, has been slow to adapt.

“I think there is a real, honestly, just like an out-of-touchness,” Mr. Bacal said.

Hillel is still one of the first places Jewish students go when arriving on campus, to meet others, do homework and enjoy a meal with friends.

“I was looking for a place where my intellectual life wouldn’t be siloed into the classroom, but would spill out to a broader community,” said Medad Lytton, a Yale senior.

After Oct. 7, he said, he “felt a strong sense of peoplehood.” A singing circle at Slifka helped him connect with others to express his grief. “It’s kind of a second home for me,” he said of the center.

Nili Fox, a junior at Washington University in St. Louis, was brought up in a religious Jewish family, and sought out Hillel as soon as she arrived on campus. After Oct. 7, Hillel was her “rock,” she said.

“It has really been helpful to know that whenever I feel uncomfortable I have a place where I was supported and loved, no matter what,” Ms. Fox said.

Other students are dismayed by what they perceive as Hillel’s uncritical view of Israel in the face of a complicated and morally challenging reality.

Some students object to Hillel houses flying the Israeli flag, which they see as a symbol of a nation that has, from Ms. Sippy’s perspective, committed war crimes.

Uri Cohen, the executive director of the Slifka Center at Yale, says the flag represents Hillel’s values.

“There are some who don’t come because it crosses a line for them, and there are many who come,” Mr. Cohen said. “Slifka is very clear. We are a Zionist institution. We are also not checking anybody’s credentials at the door.”

In January, Yale Hillel hosted a talk by Naftali Bennett, a former Israeli army commando, defense minister and prime minister, who was once considered a protégé of Benjamin Netanyahu, Israel’s current prime minister. Many Jewish students objected to Mr. Bennett’s hawkish politics.

(At a later talk at Harvard Business School, Mr. Bennett joked that he would give exploding pagers to people who disagreed with him, according to The Harvard Crimson.)

Mr. Bacal, the organizer with Yale Jews for Ceasefire, helped lead a peaceful protest against Mr. Bennett in the lobby of the Slifka Center. He did not contest Mr. Bennett’s right to speak, Mr. Bacal said, but he did not see why the event had been held in a spiritual place, a chapel where students went to pray and that contained an ark with a Torah in it.

“I think it’s a real shame, because the Jewish community at college should welcome and represent all Jews on campus to the best of its ability, no matter where they are coming from,” he said.

Another student, Netanel Crispe, a senior, said that he objected not to the speaker but to Hillel’s having allowed the protest against him. Mr. Crispe said that Slifka staff stopped him and several others from filming the protest.

He faulted Yale Hillel for trying “to play to both sides in a way that doesn’t reflect core values.”

Mr. Cohen, Slifka’s director, defended the invitation the center extended to Mr. Bennett, noting that his talk drew 300 people to a space that only held 100. “We did it out of our love for Israel and our love for Zionism, and the opportunity of giving access for our students to an influential world leader,” he said.

To illustrate Hillel’s dilemma, Mr. Bacal, the protest leader, recalled how honored he was to lead Shabbat services for the first time. His parents came to town to be there, and friends attended. But it took place around the time of the Naftali Bennett event, and one of his friends stayed away in protest.

She told Mr. Bacal she did not feel comfortable stepping into Slifka that week. “I totally get that,” Mr. Bacal said.

Alain Delaquérière, Susan C. Beachy and Sheelagh McNeill contributed research.