Hamas-Israel War: The Tunnel War Begins

According to both Hamas and Israel, the much dreaded, or anticipated depending on your perspective, battle for the extensive defensive tunnel network beneath Gaza known locally as the “Gaza Metro” has begun. Israel announced on October 29th that the I.D.F. (Israeli Defense Forces)    attacked Hamas gunmen in a tunnel and destroyed Hamas fighters who emerged from a tunnel to attack their position in northwest Gaza. Remarkably, Hamas has posted a video of what appears to be the same attack from the vantage point of fighters moving across a sandy beach towards the Israelis. While not spectacular, the Israelis have also posted a video on You Tube titled “IDF Fighting Fierce Battle in Hamas Tunnels” featuring images of its Merkava tank-backed troops assaulting Hamas’ underground labyrinth with earth excavation hoes, drills, remote cameras, and tantalizing brief footage of IDF forces operating in a concrete reinforced tunnels. And on November 1^st, even as the IDF announced that its forces were now “at the gates of Gaza city,” Hamas posted a video shot from a helmet cam of a fighter emerging from a tunnel to fire an R.P.G. (Rocket Propelled Grenade) which exploded on an Israeli tank.

Not surprisingly, history shows that tunnel warfare is hellacious and often offers an equalizer for lesser armed defending forces as it mitigates many of the advantages larger or better armed attackers possess. In the largest urban battle in history, the invading Nazi Wehrmacht met its greatest defeat of the war in the 1942-43 Battle for Stalingrad in part because the Soviet defenders made skilled use of a vast network of underground tunnels and sewers. To prevent the Red Army from popping up in their rear to attack their positions or reinforce their own besieged positions via underground passages, the advancing Germans were forced to go underground. They had to fight an attritional subterranean war against Russian “rats” that deprived them of their advantages in military technology, including air support, and cost thousands of deaths. The unprepared Germans dubbed this terrifying warfare beneath the ground that crushed troops’ morale Rattenkrieg (Rat War).

U.S backed elite Iraqi Special Forces confronted a similar underground defensive system that stymied their advances when they tried taking the massive ISIS-held city of Mosul in a bloody battle fought from 2016-17 that cost the lives of approximately 10,000 Iraqi troops. One Iraqi commander told The Washington Post;

It’s like we are fighting two wars in two cities. There’s the war on the streets and there is a whole city underground where they are hiding. Now it’s hard to consider an area liberated, because though we control the surface, ISIS will appear from under the ground, like rats.

All of these examples, and many more including the American experience of fighting the Viet Cong “rats” in the Cu Chi tunnel system north of Saigon and the tenacious Ukrainian tunnel defense of the massive Azovstal steel factory against a much larger Russian force for 80 days in 2022 offer a cautionary tale for the Israeli Defense forces. For all their vaunted technology, Israel faces the risk of an underground war of attrition that gives the enemy many advantages it lacks above ground.    

By all measures, Hamas has patiently built up a formidable defensive system beneath Gaza in terms of its scale and technology. Yehia Sinwar, Hamas’ political leader, has claimed that the militant group had  500 kilometers (310 miles) of tunnels dug under a Gaza Strip that is only some 360 square kilometers (140 square miles), making it roughly twice the size of Washington, D.C. If accurate, this makes this defense more than half the length of the New York metro system and far more extensive than ISIS’s lethal underground network which stymied the Iraqi Security Forces’ advance for nine months. This more advanced network stems from the fact that unlike ISIS, which only had two years to build up its tunnel network, Hamas has been patiently constructing its network for more than a decade and half. As its irregular forces faced intensive Israeli aerial and artillery bombardments and two major IDF land incursions in 2009 and 2014, its military leader Mohammad Deif, increasingly took his force underground. This was done so his command structure, foot soldiers and ammo depots (especially Hamas’ extensive arsenal rockets and mortars used to strike Israel from concealed fire holes) could survive Israeli incursions, artillery, and airstrikes.

The tunnels also allowed Hamas to launch offensive tunnel raids into Israel where they have bombed and kidnapped Israeli soldiers in the past. And the underground defensive-offensive structure has been well stockpiled with food and fuel, that the IDF claims on its website titled “The Underground City of Terror,” has been siphoned off from international donations. This will allow Hamas fighters to withstand a long siege. To compound matters, the entrances to the tunnels are often found in civilian apartment buildings, hospitals, mosques, fields in the desert surrounding Gaza, and even one found in a washing machine. Finding them is like finding a needle in a haystack. And according to the I.D.F. the command-and-control center for the whole spider web maze of tunnels is located underneath Gaza’s largest hospital, the civilian-packed Al Shifa Hospital.

While ISIS relied on wood and corrugated steel to reinforce its relatively shallow tunnels, Hamas has burrowed much deeper, up to 200 feet, and has reinforced its tunnels with concrete meant to protect them from Israeli bombs. Their fighters have lined the tunnels with transport rails to move rockets from point to point where they can be launched out of trap door concealed ballistic firing pads. Hamas’ tunnel corps has also built encrypted coms systems, ventilation shafts, resupply shafts, attack shafts known as “spider holes,” barracks, medical facilities, electrical generators, air conditioning, storage depots, command and control centers, mazes meant to confuse and trick invaders, bomb filled booby trapped tunnels, and dead-end defensive ambush positions. In short, Hamas has built a lethal fortress beneath a city that is meant to be a trap for the Israelis, and the Israelis know it.

Israel has no illusions about the dangers confronting it in Hamas’ terror tunnel defense because it has previously fought a terrible fight in its depths in a 50-day ground invasion of Gaza launched in 2014 to destroy tunnels into Israel known as Operation Protective Edge. During that campaign, Israeli troops entered the tunnels on the outskirts of Gaza and took casualties because they were unprepared for what laid ahead of them. The Israeli soldiers faced daunting technological challenges with detecting, fighting in, and destroying Hamas’s hidden tunnels.

IDF members who fought Hamas underground found that the experience was disorienting and surreal as gunmen popped out of nowhere to attack in dark. One said “It was like I was fighting ghosts. You don’t see them.” Each tunnel that was breached and entered had to be cleared and mapped with IDF having to place nine to eleven tons of explosives per tunnel to destroy them. The Israelis found that regular night vision goggles did not work as they relied on ambient light and there was no cell phone reception in the tunnels. To compound matters, IDF troops had to carry cumbersome oxygen supplies, respirators and chemical protective masks and intercom. Those who went down in the tunnels reported losing track of time, suffocating, and feeling like they were underwater. Unlike the Israelis, Hamas fighters knew the blueprint of the tunnel system and set up ambush points and boobytraps to repulse the invaders. Sixty-six Israeli soldiers died in the operation to destroy the tunnel threat to Israel, many in the battle below ground. And the tunnel system that cost the IDF so many soldiers in 2014 has been made vastly more lethal since then.

But even as Hamas expanded and upgraded its subterranean fortress, the IDF adapted and created a special unit tasked with entering, clearing, and destroying it. The new unit is known as the Samurs of “Weasels.” They are specialized tunnel fighting subunit of the Special Operations Engineering Unit of the Combat Engineering Corps which is informally known as Yahalom (“Diamond’). The Yahalom tunnel sub-unit is called Samur, dubbed the Hebrew word for “weasel”   is also the initials for Slikim (Caches) and Minharot (Caves or Tunnels). On its website the Yahalom “spearhead unit” describes its mission as;

Special sabotage missions, demolition and explosion of buildings, sabotage of enemy infrastructure, handling of explosives, preparing explosive devices and bombs, neutralizing enemy explosive devices, clearing complex minefields, locating, and destroying terror tunnels. At times, the unit uses robots and many remote-controlled devices, without endangering human life.

The IDF has found that the best candidates for the job were those who were introverted and “disconnected.” This specialized tunnel-fighting unit was trained to fight in a secret underground training facility that has a mockup of Hamas tunnels built with $320 million in Department of Defense funding for U.S.-Israel collaboration on “detecting, mapping, and neutralizing underground tunnels that threaten either country” according to an October 20, 2023 Congressional Research Service Report. The Israeli tunnel units have been practicing underground warfare in an artificial Palestinian city  located one hour from Gaza known as Baladia City, ("Baladia" in Arabic) part of the military base located in the Negev Desert.

During their intensive training, the Samur tunnel warriors are taught to operate underground tracked “packbot” style robots equipped with cameras like the E.O.D. (Explosive Ordinance Disposal) robot seen here disposing a terrorist’s bomb. The Tel Aviv company Roboteam has developed specialized unmanned ground vehicles for tunnel clearing missions known as “throwbots.” These remotely controlled vehicles have the ability to drive down tunnels relaying pictures back to their operators, using specialist sensors to detect objects and people and potentially detonating booby-traps with their mechanical arms. The IDF has also developed new network of sensors aimed at detecting underground tunnels boobytraps and explosives.

Additionally, defense analysts have discovered that the IDF has used gravity detectors and ground-penetrating radar to map out the spiderweb system precisely. This technology may allow them dig into tunnels at key junctures and raid them with troops and explosives or smoke them out. To assist in this specialized task, the IDF developed a new anti-tunnel weapon called novel “sponge bombs”. This device contains chemical mixture but no explosives and is used to seal off gaps or tunnel entrances. In addition to all of it its high tech, the IDF have specially trained military dogs in the Oketz (“Sting”) canine unit whose canines are trained to smell out tunnels and explosives.

But all the practice in the world with new systems and in mockup tunnels cannot prepare the Israeli “weasels” for the real thing that awaits them as they prepare for the first time to go beyond Gaza City’s suburbs, where the previous two Israeli ground invasions halted, and plunge deep into the maw of the Hamas defenses in the rubbleized kill zone of Gaza City. Harel Chorev, a Palestinian historian at Tel Aviv University’s Moshe Dayan Center for Middle East and African Studies has said “Nobody really knows what’s underground. I don’t see Israeli soldiers being able to storm these tunnels.” He may be right because the IDF has never attempted an underground mission on anything remotely this scale before. Their previous tunnel campaigns in 2009 and 2014 were limited just to the outskirts of Gaza City and did not penetrate the densely packed and heavily warned city center.

While the outcome of what is looking to be one of the most challenging battles in Israeli history remains unclear, one thing is certain. The war that the IDF has fought so far from afar with air and artillery is about to get far more costly for its troops as they commence what is potentially the largest and most dangerous subterranean campaign since Stalingrad. And in this impending battle that is made even more nightmarish by the presence of hostages that need to be rescued, the IDF will finally come with in firing and explosive range of an army of hundreds, if not thousands of vengeful Hamas Izz al Din Qassam brigade fighters who are eagerly waiting to come to grips with an enemy who has killed thousands of their countrymen and women above ground. And when the Israeli “weasels” do meet the Palestinian tunnel “rats” in the stygian gloom, the number of IDF soldiers K.I.A. (currently at 15), will doubtless soar as Hamas fighters force them to fight on their terms much the way the Soviets, Viet Cong, and Iraqis did in their bloody tunnel wars. 

Brian Glyn Williams is Professor of Islamic History at the University of Massachusetts Dartmouth and author of Counter Jihad. The American Military Experience in Afghanistan, Iraq and Syria. His website can be found at: brianglynwilliams.com