Hamas has developed a complex subterranean infrastructure known as the Gaza Metro, consisting of tunnels, command and control centers, living accommodation, stores, and contingency fighting positions. The tunnels have been in use since at least the early 1980s and have been used by various Palestinian insurgent organizations since the first Intifada, beginning in 1987. Hamas leader Yahya Sinwar claimed that Hamas has 500 kilometers of tunnel system and that the Israel Defense Forces (IDF) has damaged only 5% of it.
Tunnel warfare dates back to ancient times, with Jews using them against Romans in Judea in the first century. Tunnels have been utilized in battles such as Vimy Ridge, Messines, Somme, Vietnam, and Ukraine, including by Viet Congs, in Vietnam and ongoing conflict. The Gaza Metro is more than just any military infrastructure; it is the center of gravity (COG) of Hamas’s military wing. The Brief delves into its multifaced dimensions and seeks to flag its origins, development, and strategic implications on the ongoing war. It also focuses on the IDF’s concerted efforts in developing technologies and deploying specialized forces to detect and dismantle this clandestine infrastructure.
The tunnels in Gaza predate Hamas and were initially used by divided families to communicate and transport goods. Hamas began digging tunnels in the mid-1990s when Palestine Liberation Organization (PLO) was granted some degree of self-rule in Gaza by Israel. Early successes of Hamas using the tunnels include the abduction of IDF soldier Gilad Shalit and the killing of soldiers Hanan Barak and Pavel Slutzker in a cross-border raid on 25 June 2006.
The Gaza Strip, covering 365 square kilometers, is home to a vast network of tunnels, which could be equivalent to 10 parallel north to south tunnel systems and eight parallel interconnecting tunnels running east to west. The Gaza Metro is designed with dozens of shafts leading to tunnels at depths of between 20 and 80 meters. To create such a subterranean system, a dedicated organization, high level of technological expertise, and resources are required. Israeli officials report that Mohammad Sinwar, the brother of Yahya Sinwar, is heading the tunnel building project.
Gaza has been under land, sea, and air blockade by Israel and Egypt since 2007, and it was not expected to possess the capability or resources to dig such an infrastructure. Hamas has employed diggers using basic tools, electrical fittings, and diverted concrete meant for civilian and humanitarian purposes towards tunnel building projects. However, two tunnel systems discovered during the ongoing war, near al Shifa Hospital and close to the Erez crossing, belies this assessment.
The Israeli Defense Force (IDF) discovered the largest tunnel ever, four kilometers long and 50 meters deep, near the Erez crossing. The tunnel was reinforced with concrete, had electrical fitments, and was wide enough for a vehicle to pass through. The IDF used advanced intelligence and technological means to uncover the tunnel network, revealing over a million dollars spent on tunnel construction in 2022. The subterranean infrastructure is a crucial component of Hamas’s irregular warfare strategy, providing both offensive and defensive capabilities. It offers Hamas an asymmetric advantage, negating some of the technological advantages available to the Israeli Defense Force (IDF). Hamas has constructed this subterranean system under one of the world’s densest urban locations, complicating matters further for the IDF.
The infrastructure is designed to withstand aerial and ground bombardment, allowing Hamas to locate its leadership, combat units, headquarters, command and control centers, weapons, and supplies within the complex. This allows various military echelons to move freely between prepared contingency positions. Hamas has also located power generation, air-conditioning systems, plumbing and sewage disposal arrangements, and food supplies within the infrastructure, helping its fighters better withstand the siege laid by the IDF in the ongoing war. Hamas fighters are using tunnels for offensive operations, infiltrating IDF positions and launching surprise attacks using snipers, RPGs, and other weapon systems, with plans to cause tunnel collapse over IDF troops. Warden’s Five-Ring Model, which includes the infrastructure as the third critical ring, is related to COG, which refers to the enemy’s transportation system. Gaza Metro is essential for moving troops, warlike stores, command instructions, and intelligence around the battlefield. Neutralizing Hamas leadership is likely to have a decisive impact on the outcome of the war.
Hamas leadership plans to build safe hideouts in subterranean infrastructure, but cordoning them could expose them to IDF operations. For the moment, the IDF is unaware of the exact location of the leadership and is destroying as much of this subterranean complex as possible to cause strategic paralysis. Strange and Iron’s theory helps identify the location of COG and the impact of operations against it. Hamas is aware of the incredible capability and resources of Mossad and Shin Bet to generate actionable intelligence and the doctrinal, technological, and material superiority of the IDF to undertake combat operations. The Israeli Defense Force (IDF) is seeking to locate the al-Qassam Brigades’ leadership and fighters within the Gaza Metro, which Hamas claims is spread over 500 kilometers. Once fixed, the IDF can easily neutralize Hamas forces within the tunnel system.
The Strange and Iron’s theory provides a Critical Capabilities (CC) analysis model with three sub-concepts: Critical Requirements (CR), Critical Vulnerabilities (CV), and Critical Capabilities (CC). In Gaza Metro, CCs include subterranean infrastructure reinforced with concrete and hardened with IEDs, CRs include camouflage and concealment, and CVs include entry, exit points, ventilation, sewage, and communication infrastructure. Echevarria’s Theory postulates that COG is identified to achieve total collapse of the enemy, which is considered both an effect and an objective. However, this aspect may not be true when fighting an ideologically motivated and radical organisation like Hamas. The IDF has been aware of Hamas’s underground infrastructure and has been working towards new technologies and doctrinal concepts.
The IDF has developed several new innovations, most of them classified, such as special conical penetrators, drills, robotic systems, ground and aerial sensors, ground penetrating radars, geophones, fibre optics, microphones, special drilling equipment, radio and navigation equipment, night vision devices, remote and wire-controlled robots, training simulators, explosives and ground penetrating munitions, satellite imageries, aerostat cameras, and radars to map the tunnel system.
US and Israel have also been collaborating to develop newer technologies, with Congress appropriated US$ 320 million towards the project since 2016. Fighting enemy inside subterranean systems requires specialized units, such as Yahalom, specialist commandos from Israel’s Combat Engineering Corps, Yael Company for engineering reconnaissance, Sayfan to neutralize the threat of non-conventional weapons, explosive ordinance disposal units, and Samur, which specializes in tunnel warfare. The Israeli Defense Force (IDF) employs specialized canine units like “Oketz” for attack, search, rescue, explosive detection, and weapon location. Police and intelligence services also have specialist units like Sayeret Matkal and Yamam. The IDF’s doctrine of subterranean warfare has evolved to counter Hamas’s underground infrastructure, with soldiers only entering structures after clearing Hamas presence.
The IDF uses technologies such as tracker robots and explosives to map and clear the tunnels. During the ongoing war, Hamas prisoners have provided intelligence about the tunnels, providing excellent knowledge of the underground system under their villages and localities. The IDF uses a 70-ton Namer, one of the world’s best protected armoured vehicles, to assist in tunnel demolition. After securing the area of operation, the IDF maps the structure using ‘exploding gel’ or other technologies. The tunnel system runs for hundreds of kilometers, but it is unclear how cost and resource effective this technology is.
The IDF maintains a tunnel flooding plan, which involves deploying five large capacity pumps to draw thousands of cubic meters of water per hour from the Mediterranean Sea and flood the tunnels within weeks. However, it is still unclear how effective this tactic will be in achieving its intended objective of demolishing the underground infrastructure and is likely to contaminate Gaza’s fresh water supply.
