Now that there is a fragile cease-fire in place, it's time to ask what to do with Gaza's intricate system of tunnels.

There is, of course, nothing new about the use of tunnels in war. From ancient Jerusalem to Vietnam to Islamic State in Mosul, militaries have dealt with underground warfare for millennia. But the scale, purpose, and strategic role of Hamas's tunnel network is fundamentally different from anything we've seen before. Gaza is approximately 140 square miles, and there are at least 600 miles of tunnels below its terrain. Before the war began, there were likely more tunnels in Gaza than there were roads.

But it's not just the density of Gaza's tunnels that is unprecedented. For the first time in history, a military force built its entire strategy around its subterranean defenses, deliberately constructing tunnels beneath civilian infrastructure—schools, hospitals, homes—not to protect civilians, but to use them as human shields. This wasn't merely a tactical decision; it was the primary means by which Hamas intended to achieve its political goals.

John Spencer, a leading expert on urban warfare and military history and executive director of the Urban Warfare Institute, joins the Tikvah Podcast to discuss this unprecedented military challenge.

He has visited Gaza six times since October 7, studying these tunnels firsthand and speaking with the Israeli commanders who've had to fight in them. Today, he walks us through how Israeli forces had to remap the battlefield and reimagine warfare, learning to fight simultaneously above and below ground. We'll discuss the psychological demands of entering these tunnels, the innovative tactics that turned Hamas's greatest defensive asset into an Israeli offensive advantage, and the immense challenge that remains: what do you do with hundreds of miles of tunnels now that active hostilities have paused?