TEL AVIV—The Israeli commandos who rescued four hostages in Gaza drove a pair of battered white trucks—one displaying a soap advertisement, the other bearing a mattress and furniture on the roof. They were armed, but their main weapon was disguise, blending into a Hamas stronghold until the guns started firing.
The early June rescue mission has become the most prominent example of Israel’s famous undercover units on the battlefield in the Gaza Strip, a dangerous foray into a territory that its covert forces once found nearly impenetrable. Subterfuge is a skill set that Israel’s security services have honed for decades in the West Bank, with operatives known as “mista’arvim”—a Hebrew moniker borrowed from an Arabic term for people steeped in Arab culture.
Now, the covert unit’s presence in Gaza adds a volatile new element to the war zone, where a blown cover could be disastrous and civilian disguises sometimes constitute a war crime.
Hamas fighters are also operating in civilian garb in Gaza.
Depicted in the Netflix series, “Fauda,” the mista’arvim are lionized as heroes in Israeli society—and hated among Palestinians, who view them as menacing illegal hit squads.
Avi Issacharoff, the co-creator of “Fauda” and a former member of a military undercover unit, said the hostage rescue in Nuseirat was unlike anything he had witnessed. Most missions take place in the West Bank, where Israel has long held security control.
“The new thing is that they do undercover operations during a war inside an enemy territory,” he said. “This is what is so crazy.”
Last month’s rescue in the central Gaza city of Nuseirat relied on weeks of intelligence-gathering, commandos who practiced on replicas of the buildings housing the hostages and the positioning of thousands of soldiers to provide support, Israeli military officials said. The masquerade was vital to the daylight operation. Officials said they feared Hamas guards would kill their captives the moment they detected Israeli commandos.
“It’s not enough to find the right vehicle. You need to disguise it so it will work out in this specific territory,” said Shir Peled, a former undercover fighter for Israeli police.
In simultaneous raids on two apartment blocks, the teams maintained the element of surprise. Israeli forces, military officials said, overwhelmed the captors, extracted their bounty and battled through crowded streets to get the hostages to the beach and spirit them away on helicopters.
It is likely that undercover operatives were in the neighborhood for weeks before the rescue and present when it began to deal with Hamas’s guards, said Tomer Tzaban, a member of a small undercover military unit that operated in the Gaza Strip in the 1990s. Now Israeli intelligence is likely on a recruiting spree for local collaborators inside Gaza while mista’arvim also continue to operate there, Tzaban said.
In Tzaban’s era, Gaza was a difficult assignment. Even before Israel and Egypt imposed an embargo in 2006, there weren’t many visitors, so there were few disguises to choose from—construction worker could work, he said. Tourist couldn’t.
Gaza today is much different. The war has left more than 38,000 people dead, according to health authorities in Gaza, who don’t specify how many were combatants. Israeli military operations have destroyed swaths of the strip and displaced most of its two million people.
That makes it easier for undercover operatives. “Right now, it’s a big mess,” Tzaban said. “Every story you tell can be true.”
In February, Israeli special forces rescued two elderly male hostages held in Rafah, Gaza’s southernmost city. Just as in the Nuseirat operation, Israeli forces sneaked deep into Hamas territory without being found out.
As Israel gains further control over Gaza, it is expected to become more like the West Bank, with frequent Israeli raids to arrest or kill militants, or rescuing hostages in the absence of any deal for their freedom. That means undercover operations are likely to continue inside the enclave for the foreseeable future.
“If you want to find hostages or search for senior commanders of Hamas, you have to have people on the ground, and they can’t walk around with an Israeli flag,” said a person familiar with Israeli special operations strategy.
The undercover tactic poses legal risks for Israeli forces. In wartime, soldiers disguised as civilians risk being charged with perfidy—pretending to be someone with protected status to carry out an attack. Perfidy was established as a war crime to protect people such as health workers from becoming targets.
Hamas, a U.S.-designated terrorist group, has published videos of its fighters dressed as civilians attacking Israeli forces. The group’s military wing has uniforms. Operating in civilian clothes in Gaza enables them to mix in with the population. Israeli soldiers who fought in Gaza say it makes them suspicious of any fighting age males.
Michael Schmitt, an expert on the laws of armed conflict at the U.S. Military Academy in West Point, said perfidy doesn’t prohibit soldiers from using civilian vehicles or dressing like civilians. It does restrict masquerading as civilians to get close enough to kill or wound the enemy, but that itself is complicated. In Nuseirat, using civilian cars may have prevented an early shootout and saved lives, and the operation was done to rescue hostages, whose abduction itself he said was a war crime.
“I think it’s critically important to remember the context,” Schmitt said.
Spokespeople for the Israeli military, police and the country’s internal security service, known as the Shin Bet, declined to answer questions regarding the issue of perfidy and their undercover operations including the use of disguise.
Every undercover operation is a dangerous risk—and some backfire, or claim innocent lives.
In 2018, an Israeli team entered Gaza, some posing as aid workers, according to Hamas. After Hamas personnel became suspicious and stopped their vehicle, a shootout followed, killing the Israeli commander, a native Arabic speaker. A helicopter evacuation got the rest of the team out of Gaza.
In Nuseirat, Palestinian health authorities said 274 people were killed and nearly 700 injured in the battle that erupted around the June rescue mission. Israel’s military said around 100 people were killed or wounded, including militants and civilians caught in the crossfire. One Israeli commando was killed.
In the West Bank city of Jenin, where there are frequent Israeli raids, militants try to counter infiltrators with measures like spot checkpoints, said a Palestinian militant there. “The presence of these undercover units has left our community feeling constantly vulnerable,” the militant said.
Covert operatives became a mainstay of Israeli national security around 24 years ago, during the Palestinian uprising known as the second Intifada, when large Palestinian militant networks emerged.
The Shin Bet, the Israeli police and the Israeli military have their own mista’arvim units. The Nuseirat rescue was led by the police team, the Yamam, and aided by the Shin Bet, said officials from both agencies.
Undercover units recruit from across Israeli society, employing operatives who might blend in as tourists, clergy, doctors or ultra-Orthodox Jews, former operatives said. More than 20% of Israel’s population are native Arabic speakers.
Most mista’arvim are focused on gathering intelligence and making arrests to halt or prevent Palestinian militant attacks on Israel, former operatives said. The units seek recruits who stay calm under pressure, said Peled, who said she was Yamam’s first female operative.
Peled, who has since left the Yamam, said her disguises included being a religious Muslim, a tourist and an ultra-Orthodox Jewish woman. She never learned to speak Arabic.
During her training, her minder took her to a Palestinian bakery in East Jerusalem and gave her the simple mission of keeping him under surveillance. While she waited in line, posing as a schoolgirl, he began shouting that she was a thief. She bolted.
“It was a failure,” she said.
Abeer Ayyoub and Fatima AbdulKarim contributed to this article.
Write to Dov Lieber at dov.lieber@wsj.com
