They Refused to Serve. Now They’re Supporting Israel’s War Effort.

Made up largely of veterans and reservists, the group that calls itself Brothers in Arms started nine months ago as a protest movement against the government of Prime Minister Benjamin Netanyahu. It helped to organize giant weekly demonstrations against his plans to give the government unprecedented control over the judiciary. And many of its members vowed that they would not serve in the army if called.

But everything changed after Hamas brutally attacked Israel on Oct. 7. Not only did the reservists show up for duty, but Brothers in Arms has also transformed into the largest nongovernmental aid agency in Israel to help those affected by the war.

It is helping the military secure protective vests and helmets. It is feeding and clothing some of the perhaps 60,000 Israelis displaced from the area near Gaza after the Hamas assault. It is providing therapy to some and feeding the livestock and picking the produce of others, as well as opening a center to take care of abandoned dogs.

It has worked with A.I. experts and volunteers to comb videos and social media accounts to try to verify whom Hamas took as hostages and work out who survived and who did not. It has also provided any intelligence it can gather to the Israeli military.

But the more the group is seen positively by the Israeli public, the more those who support Mr. Netanyahu and his policies see it as a growing political force, even a threat.

On a recent day, at its main headquarters at a Tel Aviv convention center, several hundred volunteers worked on their computers and phones, using an internal app to match requests for aid and to figure out how to ship supplies to where they are needed. This is a civilian “war room,” effectively operating like a high-tech company.

It is also providing volunteers a sense of belonging and a way to serve their country — almost in spite of the current government, which they oppose. About 15,000 people a day across Israel offer help to Brothers in Arms, the organizers said.

Eden Zigo, 32, works for a cybersecurity company. When the war started, she said, “I was in a panic and I was looking for things to do, to help somehow.” She and her sister started helping the group by contributing food.

Another volunteer, Chen Benoliel, 34, a product manager, said, “It was important to be part of the national effort to do something.”

Ms. Benoliel was in Egypt, on vacation in the Sinai, when Hamas attacked, and she said that she had been afraid to return home. “I’ve never felt afraid before to be in Israel, never,” she said. “But I can’t sit at home and cry and watch TV.”

Eyal Naveh, 47, is one of the founders of Brothers in Arms. He is a veteran who served five years with Sayeret Matkal, an Israeli Special Forces unit in which Mr. Netanyahu also served.

When the government announced the legislation to overhaul the courts, Mr. Naveh considered it a “judicial coup,” he said in an interview. With fellow reservists, he quickly decided to fight the changes. “We want a Jewish and democratic state for generations to come,” he said.

But within hours of the Hamas attack, Mr. Naveh said, Brothers in Arms called on all reservists to show up for duty. “And then we created this civilian war room, or crisis center, with others from the protest, to try to do everything that civil society needs in a war.”

Mr. Naveh, who wore his dog tag over an army-green T-shirt with the group’s logo in Israeli blue and white, runs Brothers in Arms with four colleagues. Together, they decide priorities and delegate tasks to help the military and aid civilians.

They set up regional centers, too, like one near Beersheba, about 30 miles east of Gaza, in a region where they helped rescue and rehouse 2,000 families who were in hiding, he said, including people who had been holed up in fear at the site of a Hamas attack on a rave.

And they worked to retrieve DNA samples from the Israeli villages that were attacked to help identify the dead and the missing, so the army could inform the families.

Yuval Kalugny, 39, a software engineer and developer, is another volunteer with the group. “At a time of crisis and national emergency, it seemed privileged to be doing a day-to-day job,” he said.

People were feeling “so unempowered,” he said, and many here, like himself, were part of the demonstrations against the government, which he considers inadequate to the task at hand.

Mr. Kalugny is helping with logistics and data control. “I tell my wife it’s a mess here, but if I can make it less of a mess, even by a couple of percentage points, it’s a contribution.”

Danielle Green, 22, and Nitzan Averbuch, 25, are part of a feminist organization called Building an Alternative, started after the gang rape of a young woman in 2020. They joined the demonstrations against the proposed changes to the judiciary because, Ms. Averbuch said, “We understood it would hurt women and their rights.”

After the Hamas attack, the pair decided to work in association with Brothers in Arms “because it aligns with our aims,” Ms. Averbuch added.

“We’re here to take care of women’s needs,” Ms. Green said.

Building an Alternativeis concentrating on providing clothes and medical supplies to women who have been displaced and on helping them to find housing.

Since Brothers in Arms is a relatively new organization, it has not yet had to detail its funding. Alongside donations, some Israeli tech moguls, including the investor Noam Lanir, who is part of the leadership, are the financial engine of the organization.

The group’s growing popularity has also generated a backlash. During a rally in Tel Aviv on July 1 against the judicial overhaul, Brothers in Arms activists were filmed behaving violently against demonstrators protesting the Israeli occupation of the West Bank and Gaza, holding the Palestinian flag.

A photojournalist, Oren Ziv, who was there, said in an interview that Brothers in Arms activists had “forcibly prevented the anti-occupation protesters from raising a sign that read, ‘The settlers’ terror must be fought against.’” Eventually, the group issued an apology.

Before the war, some on the Israeli right had harshly criticized Brothers in Arms. Tally Gotliv, a member of the Knesset from the Likud party, tweeted in September that they were “domestic enemies” and “predators,” dividing and weakening the country.

But the group’s contributions to the war effort have impressed even erstwhile critics like the right-wing journalists Ishay Coen and Yisrael Cohen.

Mr. Naveh, who continues to express contempt for Mr. Netanyahu, says he intends to keep Brothers in Arms going after the war as a citizen’s movement and watchdog over government.

“Even if we stop the judicial coup, there are so many things to be amended,” he said. “So Brothers in Arms is here to stay, to build a stronger society, more just, in which every person feels safe and can live alongside each other.”