Until the Gaza war in the summer of 2014, both Israel and the West were largely ignoring tunnel warfare as a new threat and playing field.

Hamas’s success with multiple surprise attacks from cross-border attack tunnels on IDF troops shook Israel out of its complacency. It also led to a multiyear and multibillion-shekel effort to come up with new tactics and technologies to combat the threat.

A somewhat parallel process occurred in the US when it ran into ISIS using tunnel warfare against American troops in Syria in 2015-2016 and in preparation for a possible conflict with North Korea in 2017-2018.

A key question that came out of an impressive Israel-US conference on tunnel warfare this week at the Interdisciplinary Center Herzliya was whether initial progress in combating the underground challenge has once again overinflated Israeli confidence or whether the US has now overblown the scope of the challenge.

A clear pattern from the conference appeared to be a divergence between Israeli and US outlooks on this question after the 2015-2018 period in which both countries appeared to view the challenge with the same severity.

While many Israelis appeared ready to say they have the Hezbollah and Hamas tunnel threat on the run (no one is quite proclaiming the threat defeated), American military experts and academics were saying that subterranean warfare is destined to become an even greater challenge going forward.

Who is right?

This is a crucial question because forecasting future security challenges determines not only the division of military budgets, but also how much strategic energy and emphasis is placed on the tunnel threat as opposed to other threats.

Though militaries have huge budgets, they are also finite.

At the end of the day, Israel and the US will plan, train and build their future forces more for addressing the underground warfare challenge or for another challenge.

Both militaries do plan for multiple challenges and fronts, but what is viewed as the “burning” issue always gets priority, and secondary priorities are often addressed more passively.

Part of determining who is right is understanding how Israel and the US each got to where it is at this point.

AT THE conference, Lt.-Col. “Itai” who works for the Defense Ministry weapons research division MAFAT, gave an extraordinary presentation explaining how Israel’s journey to addressing the tunnel threat started by tossing out 600 ideas into “the valley of [ideas]death” in order to find “four to six that actually work.”

“Itai” discussed how radar was limited because the ground absorbs the energy being used for detection, which prevents energy from hitting the underground target and boomeranging back.

He also noted that the ground is much more varied in its makeup than the air, since there is a wide mix of elements in the Gazan sand and in the Lebanese rocky ground.

These varied elements, along with other phenomena underground, can either block radar or give an enormous number of false positives (a problem even with “ground-penetrating” radar) which seem to present the characteristics of a void underground that could indicate there is a tunnel.

As “Itai” put it, maybe the most important discovery that the IDF made was that “there is no one ‘Tunnel Dome’ like Iron Dome” to address the tunnel threat the way that Iron Dome addresses the threat of rockets.

Once the IDF started experimenting with a wide variety of technologies to detect sound, movement and seismic activity, it needed its operational people to become skilled at sorting the actual threatening sounds from the sounds that just sound threatening.

“Itai” disarmed many at the conference by playing a loud sound that had convinced northern Israeli residents that Hezbollah was digging under their land – and which did, in fact, sound like a jackhammer for digging a tunnel – but which the IDF later determined was a “cricket mole.”

Almost comically, “Itai” described how similar audio false positives occurred with “offenders” like “a horse kicking a fence or a neighbor’s washing machine.”

In contrast, the actual sound of Hezbollah digging underground, which “Itai” played for the conference, was far more subtle.
The IDF’s initial success was with detecting Hamas tunnels in Gaza, with IDF Lt.-Col. Aviv Amir, who also presented at the conference, being one of the leading officers in the effort.

“Itai” said that in addition to the IDF succeeding in detecting and destroying a significant number of cross-border Hamas tunnels in recent years, the IDF’s underground Gaza wall has countermeasures that will prevent Hamas’s tunnels from even reaching the wall itself.

What was noteworthy about these comments was that the wall itself, due to be finished in 2020 (though its finish date has been postponed multiple times), appeared to be secondary. The countermeasures surrounding the wall seemed to be the center of the IDF’s future underground cross-border strategy for Gaza.

The IDF has publicized details of the wall – that it will be 6 meters high and several dozen meters deep, and that around the wall will be a system designed to locate and measure tunnels using sensors, aerostats and other intelligence.

After years of flailing for solutions, it was striking to hear “Itai’s” confidence that – following the IDF’s discovery of close to 20 Hamas tunnels in recent years, plus the wall – the IDF finally has the tunnel threat from Hamas on the run.

Amir exuded a similar level of confidence presenting a series of videos showing the IDF’s December 2018 operation uncovering six Hezbollah cross-border tunnels.

Likewise, when IDF doctrine expert for the Galilee Division Col. (res.) Yuval Bazak spoke to the conference about the tunnel threat from Hezbollah in Lebanon, his emphasis was on IDF maneuvering.

He said that the IDF should not become over-obsessed with the tunnels and with how to fight inside the tunnels.

Bazak said this would be yielding most of the IDF’s firepower and communications advantages. Rather, he said, the IDF could tactically neutralize Hezbollah’s tunnels’ usefulness by having its units constantly maneuvering instead of remaining stationary.
He also said that any future conflict with Hezbollah would involve faster penetration into Lebanon by IDF ground forces. This approach, more than new technologies, is what would overcome Hezbollah’s or Hamas’s ability to translate tunnel tactics into any real gain, he said.

“Itai” said that until 2014, Iran and other threats had unduly distracted Israel from the tunnel threat. Bazak later countered that, as of 2019, the tunnel threat was no longer strategic and should not distract from more serious threats like Iran and precision-guided missiles.

IN CONTRAST, the US experts at the conference appeared to see subterranean warfare as an expanding future threat that needs to alter the entire concept and structure of the American military.

If Israel’s primary worry has been protecting its territory from invasion and protecting its troops in the rear from ambush, the US’s future concerns have to do with prevailing over enemies like ISIS, North Korea, Iran and possibly even China and Russia on those adversaries’ soil.

In recent years, ISIS used underground networks to hide from US drones and aerial strikes, to move without detection from overhead surveillance and to escape from close-quarters combat.

Special Assistant to the US Army Judge Advocate-General Michael Meier told the conference that North Korea has around 5,000 out of the 10,000 tunnels and bases underground worldwide.

He said that North Korea and other countries do not merely build tunnels. Rather, they build sometimes vast underground facilities under mega cities where pursuers can get lost in a byzantine maze of utilities pipelines and subway lines.

Many of these countries have massively reinforced command and control underground capabilities as well as the ability to deploy thousands of troops, tanks, missiles and even launch planes from underground runways.

Meier said US adversaries are likely to take the position in future conflicts that if they “stay in any one place for more than 20 minutes, they will be dead” because US surveillance satellites will expose them and then unmanned hovering US drones will take them out.

With this mentality, he expects underground fighting to become not merely an add-on issue for the US, and said it might emerge as the primary playing field for combat.

Maj. Haley Mercer of the US 82nd Airborne Division told the conference that the American military’s doctrine in 2017 shifted from specializing in counterinsurgency warfare to focusing on specializing in subterranean warfare.

She also discussed how the US is pivoting to using electronic warfare, artificial intelligence and cyber capabilities to use deception and narrative control to confront US adversaries to help shape the “battlefield” in any terrain, before any shots are even fired.
Mercer also signaled that combat on unusual dynamic battlefields like underground ones had created a greater necessity for US cooperation and openness with allies like Israel than ever before in order to crack problems.

Both Israeli and US officials described American experts visiting Hamas-Hezbollah tunnels which Israel has uncovered in order to test their new technological solutions.

Col. Patrick Mahaney, who formerly led the US Army’s Asymmetric Warfare Group, said that “the technology is constantly changing” in subterranean and other warfare.

He said that the combination of a technology-tactics arms race is “not going to end,” especially regarding “complex operating environments that are emerging,” such as underground combat in cities.

Mahaney described the US military breaking with its preferred secrecy approach, since it has had to reach out to a wide range of small start-ups to seek technological help with addressing the tunnel challenge.

In some ways, he portrayed the US military as moving into the role of project manager to try to mix and match a variety of disparate technologies into customized solutions to addressing underground challenges that it could not solve on its own.

At least since 2018, the US has even been exploring a new generation of drones that will have underground capabilities to explore and map out larger complexes. These drones’ capabilities would go far beyond the first generation of ground-based robots that Israel uses to slowly comb through the smaller tunnels used by Hamas or Hezbollah.

SO IS Israel overconfident, or is the US overly alarmist?

Part of the answer in the differing perspectives may be that Israel and the US simply are addressing different kinds of tunnel threats.
The main focus for Israel regarding underground warfare has been defensive and narrow: detecting cross-border tunnels infiltrating its northern or southern borders.

In fact, Amir revealed at the conference that when the IDF found that a seventh Hezbollah tunnel in the north only came up to, but did not cross, Israel’s border – the IDF left it alone.

In contrast, the US is playing a mostly offensive game on a global field.

The most discussed subterranean adversaries for the US are ISIS in the Middle East and North Korea, if the countries have a future conflict.

In order to defeat ISIS or radically deflate North Korea’s war-making capabilities, the US would not be defending against a mere cross-border threat to the continental US. Instead, it would be trying to “drain the swamp” of an adversary’s capabilities in tunnels on foreign soil.

Top Israeli defense figures like former national security adviser Yaakov Amidror are fond of reminding people that Hezbollah and Hamas are dynamic, adapting actors.

This means that even if Israel is feeling greater confidence in the subterranean arms race, it probably is nowhere near complacency yet.

Further, if Bazak is correct and Israel will need to drive deeper into Gaza or Lebanon in future conflicts, the IDF will likely need to engage in draining the tunnel swamp just like the US.

It will ultimately be in one of those future conflicts that we will learn whether the IDF continues to keep its eye on the ball regarding the tunnels issue or whether recent victories and a plethora of other threats once again distract it into being blindsided.

The Jerusalem Post