The New York Times reviewed, in a report, documents of the Islamic Resistance Movement (Hamas) that were seized by Israeli forces during their battles in the Gaza Strip. The documents show Hamas’ strategy of fighting in tunnels during its battles.
Among those documents, the newspaper said, was “Hamas’ 2019 Guide to Underground Combat,” which describes in meticulous detail how to navigate in the dark, move stealthily under Gaza, and fire automatic weapons in tight spaces to achieve maximum lethality. Battlefield commanders even received “by the second” how long it would take their fighters to move between different points underground.
The 2019 manual was part of a years-long effort by Hamas, long before its October 7 attack and the current war with Israel, to build an underground military operation that could survive for a long time.
Fighting in the tunnels
The newspaper reported that just one year before Israel attacked, Yahya Sinwar, the head of Hamas in the Gaza Strip, approved spending $225,000 to install blast doors to protect the brigades’ tunnel network from airstrikes and ground attacks.
The approval document stated that Hamas brigade leaders reviewed the tunnels under Gaza, and identified vital underground and surface locations that needed to be fortified.
The records, along with interviews with Israeli experts and leaders, help explain why Israel, nearly a year after the war, has struggled to achieve its goal of dismantling Hamas.
Israeli officials have spent years searching for and dismantling tunnels that Hamas could use to infiltrate Israel to launch an attack, but a senior Israeli official said “assessing the Gaza tunnels is not a priority, because an all-out war there seems unlikely.”
At the same time, officials now realize that Hamas was preparing for such a confrontation, and experts say that without the tunnels, Hamas would have had little chance against the Israeli army.
The Underground Combat Manual contains instructions on how to camouflage tunnel entrances, locate them with compasses or GPS, enter quickly, and move efficiently.
“While moving in the dark inside the tunnel, the fighter needs night vision goggles with infrared, and weapons must be set to automatic mode and fired from the shoulder,” the document, written in Arabic, states. This type of shooting is effective because the tunnel is narrow, so the shots target the kill zones in the upper part of the human body.
Israeli officials knew before the war that Hamas had an extensive tunnel network, but it proved to be more sophisticated and extensive than they had thought.
Early in the war, they estimated it to be about 250 miles long, now they believe it is twice that.
Setting up ambushes
When Israel downplayed the tunnels, Hamas prepared for underground battles, primarily ambushing Israeli soldiers near the tunnel entrances, while avoiding direct confrontations.
The strategy allowed Hamas to launch hit-and-run attacks above ground, hide from Israeli forces, and detonate explosives using remote controls and hidden cameras, slowing down Israeli military maneuvers, according to Israeli military officials and a review of photos and videos from the battlefield.
Officials said that Israeli military personnel discovered the tunnel warfare document in the Zeitoun area of Gaza City in November, and a letter from Sinwar to a military commander was found the same month south of the city. The documents were provided to The Times by Israeli military officials.
The markings on the documents are consistent with other Hamas material published or examined by The Times, and Israeli soldiers described details, such as camouflaged tunnel entrances and recently installed anti-blast doors, that match the Hamas documents.
The documents also describe the use of gas detectors and night-vision goggles, equipment that Israeli forces found inside the tunnels.
Tamir Hayman, the former head of Israeli military intelligence, said that Hamas’s combat strategy relies on covert tactics, and this is one of the main reasons that they have been able to withstand the Israeli army so far.
Tunnel engineering
Hamas has other tunnels that are sophisticated command and control centers or arteries linking underground weapons factories to storage facilities, and some tunnels also serve as communication centers.
The newspaper reported that last winter, Israeli forces found an underground Nokia communications system. These systems provide voice and data tones, and can serve as a switchboard for an underground communications network, but the features require additional equipment and it is not clear what capabilities Hamas possesses.
Israeli officials say Hamas is holding Israeli prisoners underground, so every tunnel must be investigated and cleared, they say.
“The tunnels affect the pace of operations,” said Daphne Richmond-Barak, a tunnel warfare expert at Reichman University in Israel. “You can’t advance and you can’t secure the terrain.” “You’re dealing with two wars, one on the surface and one below.”
An Israeli special operations officer said that as soldiers approached the tunnels, Hamas sometimes blew up the ceilings, causing collapses that would block the way inside the tunnels.
It could take dozens of soldiers about 10 hours to destroy a section of the tunnel, according to a senior Israeli officer and expert on tunnel warfare. Last year, the Israeli military discovered a tunnel 250 feet deep, the height of a 25-story building, and the military said it took months to destroy it.
An Israeli military official said it could take years to destroy the entire tunnel network.
Construction cost
The Israeli military estimates that building a primitive tunnel about a half-mile long cost Hamas about $300,000, and Richmond-Barak said Sinwar’s letter highlighted the cost and complexity behind the effort.
“The brigades will be given money according to importance and necessity,” Sinwar wrote in the letter, which could indicate where the group expects the most intense fighting. Sinwar authorized the most money for blast-proof tunnel doors in northern Gaza and Khan Younis. In fact, some of the fiercest fighting during the war took place in those areas.
The anti-blast doors seal the tunnels from each other and from the outside, protecting against explosions and breaches. They also hinder the Israeli army’s use of drones to inspect and map the tunnels.
The Israeli army has repeatedly encountered anti-blast doors while combing the tunnels.