Hamas tunnels under Gaza will be a key battlefield for Israel

Underground warfare is terrifying, claustrophobic and slow.

Students of urban warfare divide the battlefield into four planes. One is the sky above cities, increasingly thick with drones. Next are the buildings that extend upwards, offering vantage points and hiding places. A third is the street scape: the lattice of roads, alleys and paths that form a city's peacetime arteries. It is the fourth the tunnels lying beneath that will present the greatest challenge to the Israel Defence Forces (IDF) when they begin their invasion of the Gaza Strip in the coming days.

The first smuggling tunnels in the area were built by Bedouin clans on both sides of the Egypt-Gaza border after 1981, when Israel and Egypt demarcated the border. The first known tunnel attack from the strip occurred in 1989. But it was in 2001 that Hamas, the militant group that would later take over the territory, after Israel withdrew in 2005, began construction of a remarkable subterranean network. Its initial aim was to smuggle in material and arms from Egypt. But the tunnels had manifold other uses.

Commanders could hide in them and use them to communicate without relying on Gaza's phone network, tapped by Israel. They provided hiding places for weapons and ammunition. Hamas could use them for ambushes during Israeli ground wars in Gaza. And they allowed cross-border raids into Israel for attacks and abductions - such as the kidnapping of Corporal Gilad Shalit in 2006, a raid that later helped Hamas secure the release of more than 1,000 Palestinian prisoners. Hezbollah, the Lebanese militant group, built similar tunnels on the Israel-Lebanon border, though most were destroyed in 2018-2019.

The military rationale of such tunnels was ultimately to erode Israel's way of war. "In 2008," said a Hamas commander, reflecting on a brief but intense war over Gaza that winter, "the air strike and air surveillance (by Israel) took us by surprise... so we made strategic plans to move the battle from the surface to underground."