Is Israel Winning the Underground Fight?
Daphné Richemond-Barak
The past few weeks have once again brought Israel’s ongoing battle against tunnel warfare to the spotlight. Tunnels drew the country to the brink of war with Hamas in mid-November, when the militant group fired 500 missiles into Israel in response to the killing of a central figure in Hamas’s tunnel warfare program. Then, just three weeks later, the Israel Defense Forces launched Operation Northern Shield along the country’s border with Lebanon with the aim of destroying cross-border tunnels dug by Hezbollah over the past decade.
These events come as a sharp reminder that tunnel warfare has become as central to modern conflicts as it was in centuries past. Tunnels have been a feature of war since time immemorial, typically as an anti-personnel tactic or as a means to overcome fortifications. Their appeal has grown on the modern, high-tech-dominated battlefield, where surveillance and intelligence capabilities can detect virtually any movement of personnel or vehicles above ground. The escalation in Gaza and the discovery of four cross-border tunnels at the Israel-Lebanese border, capture both the complexity of subterranean threats and the challenge of finding solutions to them.
Indeed there is no quick fix to the use of violent underground tactics by actors like Hamas, Hezbollah, Al Qaeda in the Islamic Maghreb, and ISIS. The reemergence of underground warfare on the contemporary battlefield calls for a robust and multifaceted response combining technological solutions, military preparedness, and often patience, as demonstrated by Israel’s years-long monitoring of Hezbollah prior to Operation Northern Shield.
The magnitude of problem can be, like tunnels themselves, much greater than it seems on the surface. Last month, Israel announced that it had destroyed fifteen Hamas tunnels dug under the Israel-Gaza border in 2018 alone. After over a decade of infiltrations, kidnappings and attacks from below the surface, this came as reassuring news. But just a few days later, the unveiling of a network of tunnels at Israel's northern border put to rest any hope that the subterranean threat had been contained.
Israel's investment in anti-tunnel solutions accelerated following its 2014 confrontation with Hamas, in which underground attacks featured prominently. Harnessing its deep technological capabilities, the IDF developed sophisticated tunnel mapping, detection and fighting techniques that purportedly include a secret tunnel-destroying weapon and the digging of a sensor-equipped underground barrier. In keeping with the start-up mindset that so characterizes the country, the IDF established a special tunnel unit (coined “The Lab”) where young algorithm-savvy youths work alongside experienced military experts in order to fight underground wars.
While tempting, relying exclusively on technology will not work. Geology, urban planning and tunnel specs vary greatly, making it impossible to formulate one-size-fits-all methods of detection and neutralization. For Israel, finding Hezbollah's tunnels required much more than simply replicating the efforts undertaken at the Gaza border. Northern Shield demonstrates that the construction of underground barriers or the development of sophisticated detection technology only pays off as part of a holistic strategy that involves the creation of specialized units, a true understanding of the terrain, and a re-thinking of military training, operating procedures, and intelligence-gathering techniques.
Anti-tunnel measures wielded without a clear end game in mind tend to be enormously destructive, and their impact tends to be short-lived. The US lost countless men in the Pacific as it fought entrenched Japanese forces during World War II (Hacksaw Ridge is a good recent chronicle), and again in Vietnam nearly three decades later. French forces were dumbfounded in 2011 by the difficulty of finding and clearing caves in Mali’s Valley of the Ametetai, where AQIM had established its stronghold. Tunnels expose the limits of modern precision warfare, requiring destructive measures with potentially high collateral damage: B-52 bombers in Vietnam; GBU-43/B Massive Ordnance Air Blast (MOAB or Mother of All Bombs) in Afghanistan; mass flooding with sewage water in Egypt; heavy artillery bombardment in Mali; and bulldozers and airstrikes in Israel.
Operation Northern Shield appears to be different. The operation was meticulously planned for months and is designed to detect and neutralize the Hezbollah tunnels along the entirety of Israel’s northern border. As such, one hopes it is more likely to achieve its long-term objectives, with less destruction and broader international support.
Still, it might be too early to declare victory in Israel’s battle against underground warfare. First, Israel has publicly identified four tunnel complexes; there may be many more, and there is no certainty they will all be uncovered. Hezbollah might also use an undetected tunnel to surprise Israel in the midst of the operation. Second, Israel has thus far only booby-trapped the tunnels it has discovered; it has not destroyed them due to its reluctance of entering Lebanese territory and the tunnels’ proximity to civilian areas. If the American experience in Afghanistan or Vietnam is any guide, tunnels remain a threat until they are destroyed, and neither isolation nor booby trapping or monitoring is sufficient.
On the modern battlefield, what’s most required is therefore a recognition of the risk as a threat in its own right, and the allocation of the resources to counter it. Winning the underground fight means developing long-term strategies, preparing military forces for underground operations, and harnessing technology to reveal what is invisible to the human eye and modern surveillance capabilities. As Israel has painfully learned in Gaza, a highly reactive policy is less likely to achieve results than the patient, comprehensive approach it has chosen to follow on the Lebanese border.