Executive Summary
The global usage of the tunnel for transnational crime, dissident movements, and even governments and militaries makes it a persistent challenge for security and law enforcement agencies. State actors, like North Korea, and non-state actors (such as Hamas), use tunnels because they are hard to detect, safely clear, and close, even with advanced technology. Additionally, efforts to counter subterranean operations, such as in Gaza, have shown limited effectiveness. At the same time, criminal groups such as Mexican cartels are using subterranean channels to smuggle people and goods, with growing adoption, especially for human smuggling.
