Recently, NEWSREP Editor-in-chief Jack Murphy reported on the U.S. military’s standing plan to infiltrate Iranian underground bunkers housing integral elements of the nation’s nuclear apparatus. If war between the United States and Iran were ever to come to fruition, these facilities (commonly referred to as hardened and deeply buried targets, or HDBTs) would be among America’s top priorities. But taking them out of commission would require a more dramatic approach than America’s preferred method of warfare by ballistic missile.

Many of these HDBTs are constructed deep underground, often by tunneling into mountains. The natural barrier provided by 2,000 feet of rock would, in some cases, render even America’s bunker-busting munitions useless. Instead, infiltrating and destroying these facilities would fall to America’s elite counterterrorism unit, the 1st Special Forces Operational Detachment-Delta, or Delta Force.

Although Delta has been training for these potential underground combat operations in Iran for years, the risks associated with such an operation have grown in tandem with the increasing number of potential enemy states—including North Korea, China, and Russia—all of which maintain (or are rumored to maintain) sizable underground facilities meant to shield against weapons of mass destruction and potentially afford protection to command and control elements from surveillance or engagement.

Soldiers of 2nd Stryker Brigade Combat Team, 2nd Infantry Division, prepare to clear a corridor during subterranean operations training. (U.S. Army)

As Jack Murphy pointed out in his NITRO ZEUS piece, “Numerous countries have sought to conceal and protect vulnerable military resources underground inside facilities hardened with reinforced concrete, vault doors, internal environmental systems, and more, such as the United States has done at the Cheyenne Mountain Complex.”

Put simply, fighting in enclosed spaces deep underground, where communications are limited and the stakes are at their highest, isn’t just a tactical nightmare, it may also become a pervasive part of what nation-level warfare looks like in the 21st century.

It’s likely with this concern in mind that America’s Defense Advanced Research Projects Agency, or DARPA, has issued a request for information regarding advanced technologies and methodologies that can be employed for the “3D mapping and surveying of underground environments.”

“What makes subterranean areas challenging for precision mapping and surveying, such as lack of GPS, constrained passages, dark or dust-filled air, is similar to what inhibits safe and speedy underground operations for our warfighters,” said DARPA Tactical Technology Office (TTO) Program Manager Timothy Chung. “Building an accurate three-dimensional picture is a key enabler to rapidly and remotely exploring and searching subterranean spaces.”

If you’ve seen the film “Prometheus,” this effort may seem familiar. In the movie, crew members deploy floating drones that use lasers to quickly map out the subterranean cave complex they’re exploring.

It doesn’t seem likely that DARPA’s cave-mapping drones will defy gravity like those depicted in “Prometheus,” but with small drone technology rapidly advancing, a “floating” mapping device doesn’t seem entirely out of the question. Of course, propulsion is far from the only technical hurdle faced in this initiative. Maintaining connectivity to the operator, processing the data captured and rendering it in a usable manner, and even concerns about battery life versus added weight are among the litany of hurdles developers will need to either mitigate or eliminate in order to make such a device a reality.

A soldier assigned to 2nd Battalion, 1st Infantry Regiment, 2nd Stryker Brigade Combat Team, 2nd Infantry Division, provides security during subterranean operations training. (U.S. Army)

In many ways, special operations war-fighters operating in these tunnels will be doing so without any access to external digital or communications infrastructure, meaning the mapping system will need to be entirely self-contained between the probe and the operator’s gear. Cloud computing or outsourcing any of the computational work via any sort of network simply won’t work beneath 2,000 feet of rock

The challenges DARPA faces in this endeavor are not insignificant by any stretch of the imagination, but a breakthrough in this sort of technology could provide American and allied forces with a much-needed advantage in what would be sure to be brutal fighting inside confined spaces. America’s special operations troops may be the best trained in the world, but training doesn’t stop bullets. In tunnel warfare, a defender’s familiarity with the space, the terrain, and any potential hazards can offset a significant training advantage had by the attackers.

Despite not quite garnering the same sort of attention as programs like the F-35 Joint Strike Fighter or new hypersonic missiles, tunnel-mapping technology may prove to be the most valuable tech in America’s war-fighting arsenal. After all, fast-moving missiles may help win a conventional war, but the only way to win a nuclear one is to prevent it from starting in the first place.