Learning From Terrorist Tactics: Preparing For Subterranean Warfare

I posted an article last year on Subterranean Warfare in Israel, Gaza and the West Bank and it now looks like this nasty type of fighting is definitely going to be part of the landscape in the battle zones in Syria and Iraq as well. -SF

Last year, members of Jabhat al-Nusra, al-Qaeda’s Syrian affiliate, dug a tunnel leading to the Syrian Air Force Intelligence building in Aleppo and detonated a massive bomb in an attempt to destroy the facility. Reported globally, this event was by no means a rarity in the ongoing Syrian civil war. As Benjamin Runkle warned last year, the United States and its allies must prepare for the subterranean future of warfare. His article was a broad and useful overview of the various threat actors using tunneling to negate the advantages that airpower and other technologies provide to Western militaries. As America increases its military involvement in Iraq and Syria, a more detailed look at the military significance of such structures is warranted. As of February of this year, there were nearly 4,500 U.S. troops in Iraq. Regardless of the merits of further intervening in the conflict, it is a fact that the United States and its allies are sending increasing amounts of troops to the region. Whatever the intentions of American leaders, this expanded presence is almost certain to result in greater contact with a variety of hostile forces. Al-Nusra, the Islamic State of Iraq and the Levant (ISIL), the Syrian government, and other factions in the war have all used tunnels to great effect throughout the conflict. U.S. and allied militaries must thus understand and prepare for subterranean warfare.

The Subterranean Landscape in Iraq and Syria

Both Syrian regime and rebel forces have burrowed a vast series of tunnels into the area around Damascus. Given the ever-shifting tide of battle, these structures have become neutral parts of the battlespace, rather than dedicated mobility corridors for one side or the other. Teams of up to 300 insurgents have labored with shovels and pick axes to dig these tunnels. The Free Syrian Army has reportedly even employed architects to design a tunnel, which it used to infiltrate a government military base near the town of Erbin. Outside of the Syrian capital, regime forces claimed they had destroyed a subterranean network near Harasta in June 2015. This massive underground structure includedtunnels up to 200 meters in length equipped with lighting and ventilation ducts. Later that year, ISIL built an elaborate series of passageways in the border town of Sinjar during its battle with Kurdish forces. Likely constructed with jackhammers and hand tools, the network featured multiple exit points fortified with sandbags to protect against American-dropped ordnance. The Islamist group also smashed holes in walls between buildings to allow covered, aboveground transit in the face of withering American airstrikes. As part of ISIL’s tenacious defense of the area south of Mosul, the group has constructed an underground “city within a city” to protect its fighters against advancing Iraqi government troops.

Tunneling in the Offense

The various warring factions in Syria and Iraq have not only used burrowing below ground as a defensive or force protection measure, but they have also used tunnels to deliver troops and explosives against their enemies. When they threatened the Iraqi capital in the late summer of 2014, ISIL made use of Saddam-era subterranean routes to evade Iraqi Security Forces, hide from their aircraft, and deny them rear-area security. In the battle for Homs in November 2015, al-Nusra built passageways 15 meters underground, some of which stretched for 3 kilometers. According to Syrian government soldiers, the primary purpose of these structures was to allow insurgents to encroach on regime fortifications by maneuvering in a covered fashion.

In an almost herculean effort, another rebel group reportedly spent seven months building a tunnel under the Syrian Army’s Wadi Deif base. Instead of using the subterranean passageway to deploy troops, the rebels used it to detonatealmost 60 metric tons of explosives in May 2014 and kill at least 20 soldiers. Possibly following the lead of other groups, ISIL detonated six metric tons of explosives under an Iraqi army headquarters in Ramadi in March of 2015. The insurgents had spent two months digging a 240 meter tunnel under the structure. Syrian regime forces have likewise maneuvered toward rebel checkpoints under the surface to detonate explosives below their unsuspecting targets.

Read the Remainder at War on the Rocks