For decades, underground warfare was viewed as a niche military problem. Today, it has become a defining feature of modern conflict. From Hamas's extensive tunnel network beneath Gaza and Hezbollah's underground infrastructure in Lebanon to Iran's hardened missile facilities and the expanding subterranean systems in Ukraine, North Korea, and China, military forces are increasingly using the underground for protection, command and control, logistics, and maneuver. As drones, persistent surveillance, artificial intelligence, and precision strike make the surface battlefield more transparent and lethal, the strategic value of operating beneath it continues to grow.

In this episode, John Spencer is joined by Asher Katz, cofounder and CEO and of Traysar Industries and a former member of the Israel Defense Forces' elite Yahalom unit. Their discussion examines the unique challenges of fighting below ground, the evolution of Hamas's tunnel strategy, lessons emerging from Ukraine, why destroying tunnels is often far more difficult than locating them, and why militaries must rethink doctrine, organizations, and capabilities for this increasingly important battlespace dimension.

In this episode, John Spencer is joined by Stuart Lyle, urban operations research lead at the United Kingdom’s Defence Science and Technology Laboratory, for a discussion on one of the most overlooked but critical aspects of preparing for future war: urban warfare training facilities. The conversation includes a survey of major urban warfare training centers across NATO member states, including live-fire defensive buildings, subterranean training complexes, trench systems integrated into urban terrain, and facilities designed to demonstrate the real effects of weapons on buildings, cover, and urban infrastructure. Spencer and Lyle examine the persistent challenge of balancing scale and realism in urban warfare training, examining whether existing facilities—even the most innovative ones—adequately prepare soldiers for the realities of high-intensity urban combat. They discuss what current training sites get right, where they fall short, and what militaries must do to better prepare for the decisive battles increasingly fought in cities.

John Spencer is joined on this episode by Colonel Kevin Black, commander of the 11th Armored Cavalry Regiment, the Army’s premier opposing force at the National Training Center. Their discussion centers on the battle for Razish—a fight in which every rotational training brigade must attempt to seize a dense, multistructure city defended by a highly adaptive enemy. Col. Black explains how the Blackhorse Regiment replicates a near-peer threat with a fraction of the force, using repetition, terrain mastery, and decentralized execution to consistently defeat rotating units. The conversation then moves beyond Razish to examine how the character of warfare is changing and what that means for urban combat. It explores the emerging concept of a battlefield dead zone, where persistent surveillance and precision fires make movement lethal, and the notion of an empty battlefield, on which dispersion hides forces even as combat intensifies. The episode concludes by highlighting common mistakes made by attacking units—from overcomplicated planning to failure to mass at decisive points, and emphasizes the enduring advantages of the defense in urban terrain.