Inside Hamas’s Elaborate Terror Tunnel Network
This article was written by Alexander McDermott, Policy Fellow 2023-2024, and originally appeared in Reaction. The views in this article are the authors own.
The date is 12 September 2023. James Cleverly is greeted with rapturous applause by the 1,000-strong audience at Israel’s Reichman University, who have gathered for the twenty-second International Institute for Counter-Terrorism Conference.
Packed into the lecture theatre is a star-studded cast of defence and military experts, including three former IDF heads, two directors of international intelligence agencies, and one Israeli defence minister. The then-Foreign Secretary’s speech – stressing the value of a UK-Israel relationship in the fight against global extremism – rounded off three days of discussion between scholars and security industry leaders.
Three weeks later, Hamas sprung a devastating assault on southern Israel. The terrorist group bulldozed security fences, destroyed civilian homes with rocket barrages, and massacred fleeing Israelis under hails of gunfire.
Many of the ICT Conference’s audience have been amongst those scrambling to direct Israeli intelligence resources towards an effective retaliation. Much of the focus has been on Hamas’s “Gaza Metro” – the underground tunnel network below Gaza. According to Hamas, the tunnels have now reached 500km in length, roughly the distance from London to Luxembourg. Home to armouries, food warehouses, and aerial weapons factories, these tunnels are an essential part of Hamas’s terror infrastructure.
Tunnel construction began after Israel’s withdrawal from Gaza in 2005 but accelerated following Hamas’s occupation of the Strip in 2007. Using similar techniques to Syrian rebel fighters in Aleppo and ISIS terrorists in Mosul, Hamas initially built 2.5km of underground passageways into Egypt to smuggle goods, fuel, and weapons. These tunnels have since been used to kidnap IDF solider Gilad Shalit – captured after Hamas entered Israel near the Kerem Shalom border crossing in 2006 – and the imminence of their threat to the civilian population was realised in 2013, when a 1.6km tunnel to the Kfar Aza kibbutz was discovered.
The IDF now believe that hostages taken in the attack are being transported underground. In a media appearance last month, 85-year-old Yocheved Lifshitz – recently released from Hamas captivity – recalled travelling through a “spider web of tunnels” towards a bunker, where she was held with twenty-five other Israelis for over two weeks.
The tunnels are also reported to house high-readiness Hamas terrorists, allowing them to quickly appear and retreat from urban battlegrounds, taking on minimal casualties. Senior Hamas leader Ali Baraka boasts that there are 40,000 fighters from the Al-Qassam Brigades – Hamas’s military wing – currently “waiting for the battle” underground, with 20,000 reinforcements available from across the other cadres.
However, this is not a scenario that Israeli intelligence services will be unfamiliar with.
In July 2014, following a notable increase in the exchange of rocket fire between Hamas and Israel, the IDF launched the “Operation Protective Edge” ground offensive into Gaza. Its aim was to destroy the network of “terror tunnels” used by Hamas to cross the Israeli border. IDF forces threw smoke grenades down suspected tunnel entrances, allowing them to discover ventilation shafts, before digging down to breach the tunnel with armoured excavators and explosive charges. This method reportedly resulted in the “neutralisation” of 32 tunnels, 14 of which crossed from Gaza into Israel.
Despite this experience, tunnel warfare – and the intelligence collection which supports it – adds a new dimension to Israel’s fight against Hamas. In 2021, Israel completed the installation of an underground concrete wall along the Gaza border, fitted with advanced sensors to detect tremors caused by Hamas’s tunnelling. The 65km-long barrier took three years to build, consuming $1.1 billion, two million cubic metres of concrete, and 1,200 workers. Should it emerge that underground tunnels were used by Hamas in the October 7 attacks, it may confirm reports that the terrorists were able to dig underneath this concrete wall and bypass Israeli security systems.
It is also possible that the sensors built into the concrete wall – designed to locate cavities and track sounds of shovelling or movement – are rendered ineffective in a battlefield of explosions and rumbling armoured vehicles. Geologists have commented that the soft, silty lithology of Gaza allows for tunnelling to be done with hammers and chisels, rather than electric diggers which are more likely to disturb the sensors.
Whilst Israeli military intelligence will have to grapple with these changes to warfighting against Hamas, the infantry must also adapt to a new style of Operating in Built Up Areas (OBUA). Entrances to many tunnels are hidden in the basements of homes and medical facilities, or remote rural environments, making them hard to spot for IDF IMINT (imagery intelligence) operatives. Even if these entrances are detected, many are booby-trapped, fitted with tripwires and motion-triggered bombs. The sprawling network of tunnels, complete with narrow pathways and escape routes, also leaves Israelis vulnerable to the launch of further surprise attacks by Hamas.
By fully committing to a ground operation in Gaza, the IDF will have to overcome these strategic challenges of tunnel warfare. American author Edward Luttwak writes, “standard tactics and weaponry are often not suitable inside a subterranean setting”, for instance, “the sound emitted by a weapon being fired is also amplified”, meaning that soldiers will need “intensified hearing protection”.
“In some cases, it can be impossible to breathe without oxygen tanks in tunnels”, adds John Spencer, Chair of Urban Warfare Studies at West Point’s Modern War Institute. “It can also be impossible simply to see. Most military night vision goggles rely on some ambient light and cannot function when it is entirely absent. Any military navigation and communication equipment that relies on satellite or line-of-sight signals will not work underground”.
Of all the operational challenges that IDF forces will face during a ground operation in Gaza, the terror tunnels are perhaps the most difficult to navigate. They will remain Israel’s greatest counter-terrorism headache if IDF intelligence and infantry units cannot successfully destroy the entirety of Hamas’s network. If it is not viable to blow up a 500km-long system of concrete-reinforced, well-equipped passageways, then the IDF must adapt to many onerous months of Close Quarter Battle (CQB) in a totally alien environment. Robots, sniffer dogs, and elite combat engineers from the IDF’s Yahlom unit can bolster Israel’s arsenal for a new kind of combat, but it remains clear that the underground fight against Hamas will be the hardest one.
It may be that Israel tries to bring its battle against Hamas entirely to the surface, slimming the terrorists’ advantage. Considerations will have to be made as to whether water, sewage waste, or gas is used for flushing out the tunnels, with respect to international law and ramifications from the morality of these methods.
The terror tunnels are proving to be a wicked thorn in the side of Israel. Ultimately, whatever the IDF’s next steps to defeat Hamas are, they must act intrepidly, intelligently, and innovatively.
