Photo: IDF Spokesperson’s Office
Shimon Sherman (JNS)
Tension has spiked across Israel’s northern border over the past week following the alleged killing by Israel of Hamas deputy leader Saleh al-Arouri in a suburb of Beirut.
This escalation comes nearly three months into fighting that erupted along the Israel-Lebanon border in the wake of Hamas’s Oct. 7 massacre.
“The situation is already essentially war—they [Hezbollah] are killing our soldiers and bombing our houses. The reality is completely untenable for anyone who lives in the north,” said Tal Finkelstein, a resident of the northern city of Kiryat Shmona.
The continued fighting has led the Israeli leadership to call for Hezbollah to withdraw its forces from the northern border. Both Defense Minister Yoav Gallant and Israel Defense Forces Chief of Staff Lt. Gen. Herzl Halevi have said that Israel is willing to use force to push the terror group further north.
These developments have raised questions about Hezbollah’s offensive and defensive capabilities generally, and more specifically regarding the vast terror tunnel network that Hezbollah is believed to have been developing in preparation for a potential war with Israel.
Operation Northern Shield
The issue of the Hezbollah tunnel network was thrown into the limelight in 2018 when Israel launched “Operation Northern Shield.” Over a period of six weeks, the IDF exposed six tunnels dug from Lebanon into Israel.
According to the IDF, these tunnels were “designed to secretly transport Hezbollah terrorists into areas near Israeli communities in the northern Galilee and to then to attack those communities.” The largest tunnel, originating in the southern Lebanese town of Ramiyah, was 260 feet deep—equivalent to a 22-story building—more than 3,000 feet long and extended nearly 250 feet into Israel. It featured air-conditioning, phone lines, rail tracks and staging grounds for cross-border invasions.
According to Maj. (res.) Tal Beeri, head of research at the Galilee-based Alma Research and Education Center, the discovery of these tunnels overturned the military thinking that the rocky terrain of southern Lebanon would present a major obstacle to the development of a substantial tunnel system by Hezbollah.
The ‘land of tunnels’ report
In 2021, a report published by Alma further shed further light on the issue. “In 2008, we uncovered an indication from a Christian Lebanese source, describing a big project by Hezbollah in extensive areas of Southern Lebanon, which began east of Sidon,” said Beeri.
Beeri and his research department began gathering an impressive collection of evidence, including eyewitness testimony from residents, videos, and maps, all of which pointed to a highly developed Hezbollah tunnel network. A central element of their research was an open-source map that the institute found depicting 36 polygons spread across Southern Lebanon.
“In our assessment, these polygons mark Hezbollah’s staging centers as part of their ‘defense’ plan against an Israeli invasion of Lebanon. Each local staging center possesses a network of local underground tunnels. Between all these centers, an infrastructure of regional tunnels was built, interconnected [with] them,” said Beeri.
This assessment was a product of correlating reports of construction or fortification work with no visible above-ground work, and areas marked on the map.
“They [Lebanese civilians] didn’t understand why Hezbollah was stopping them from approaching [these areas]. What they could see resembled construction work, sand, digging and concrete in the area. But nothing was being built above ground. They saw Iranians and other foreign nationals that they later realized were North Koreans,” said Beeri.
According to the Alma report, both North Korea and Iran were central to the design and construction of the tunnel network. The initial tunnel-digging projects began in the early ’80s and greatly ramped up in the late ’90s under North Korean supervision.
“North Korean advisers significantly assisted Hezbollah’s tunnel project. Hezbollah, inspired and supported by the Iranians, saw North Korea as a professional authority on tunneling, based on the expansive North Korean experience that has accumulated in building tunnels for military use since the 1950s,” said Beeri.
In the aftermath of Israel’s Second Lebanon War in 2006, Hezbollah’s relationship with North Korea diminished in favor of Iranian aid. By 2014, Hezbollah had received all it needed from the Koreans and began setting up its own “civilian” companies to expand the project further, according to Beeri.
The report exposes a vast and enormously complex system of Hezbollah tunnels throughout Lebanon. Beeri estimated that the total length of all the tunnels reaches into the hundreds of kilometers. The subterranean system features technologically complex tunnels with multiple connecting branches. Some are large enough for pick-up trucks with multi-barrel rocket launchers to drive through.
“It’s not just about a local network of attack tunnels and infrastructure in or near villages, but an inter-regional tunnel network,” said Beeri. A further revelation of the research is that the Hezbollah tunnel system is not solely contained to Southern Lebanon, but extends to an inter-regional level, connecting south Lebanon with the Beirut area and with a region of north Lebanon on the Syrian border, where Hezbollah also has a powerful presence. In May 2021, Kan News independently confirmed that a Hezbollah tunnel connected south Lebanon with Beirut.
The Alma report broke down the tunnel system into four types. Attack tunnels are the central arteries of the underground network. These tunnels are sometimes large enough to drive midsize trucks through and are crucial to Hezbollah’s offensive strategy. Beeri explained that certain surface-to-surface ballistic missiles used by Hezbollah are carried on trucks, and the large tunnels allow them to carry out fast, mobile launches while hardly exposing the location of the launch site.
Tactical tunnels, of the type that were discovered in “Operation Northern Shield,” are usually based near Lebanese villages and are primarily used by infantry soldiers to move secretly, and then emerge quickly for an attack before returning to rearm and rest. Another type are the proximity tunnels, similar to tactical tunnels but designed to get Hezbollah fighters near the Israeli border, from where they can attack. A final type, called explosive tunnels, are filled with explosives and are placed in strategic positions to be remotely detonated when IDF troops approach.
The current threat
The extensive nature of the currently known Hezbollah tunnel system raises concerns about unknown tunnels leading into Israel. Over the past years, many residents of northern towns close to the Lebanese border have reported hearing sounds of construction work under their communities.
“When we said they were digging, the military told us we were imagining things, and we don’t know if all the tunnels were found then,” Yaniv Turgeman, chairman of the committee of Moshav Stula in the Upper Galilee said in a recent interview. Addressing these concerns, IDF Maj. Gen. Ori Gordin, head of Northern Command, said this week that soldiers are “conducting searches to locate any terrorist infrastructure both above and below the ground. If a threat is identified, we will not keep it a secret from anyone.”
As fighting on the northern border continues to escalate, the threat of Hezbollah’s tunnels becomes ever more relevant. As a result of the fighting, several Israeli soldiers have been killed and over 80,000 civilians have been evacuated from the northern communities. Hezbollah announced the death of 143 of its fighters since the outbreak of the hostilities on Oct. 7.
“We are not returning to the previous situation,” Chief of Staff Halevi said in a statement last week, emphasizing that the army is preparing for combat in Lebanon to drive Hezbollah away from the border.