New detection technologies tracking terrorists through thick concrete, underground tunnels, and caves

In April  2017, the U.S. military dropped the most powerful non-nuclear bomb ever used in combat on a tunnel complex in Afghanistan’s Nangarhar province. The airstrike targeted the Islamic State’s Khorasan branch. The use of the GBU-43/B Massive Ordnance Air Blast weapon, the so-called “Mother of All Bombs,” highlighted the growing threat posed by adversaries’ underground structures. Gen. John Nicholson, commander of U.S. Forces-Afghanistan, cited the challenge of dealing with subterranean targets to justify the use of the bomb, also known as the MOAB. “As ISIS-K’s losses have mounted, they are using [improvised explosive devices], bunkers and tunnels to thicken their defense,” he said in a statement released after the attack. Additionally, hostile regimes such as North Korea are believed to be hiding WMD technology and other weaponry in underground facilities that the U.S. military might need to locate.