The “Gaza metro” is nothing if not formidable. The network of tunnels built by Hamas beneath the enclave is hundreds of kilometres long. It houses command centres, weapons dumps and stores of food and fuel. It gives Hamas’s fighters the ability to ambush Israeli troops, and to shelter from bombs and artillery. Read all our coverage of the war between Israel and Hamas Israel’s stated goal is to destroy Hamas.
Buried fibre-optic networks can detect underground vibrations by the “backscatter” they cause in the photons travelling through the cables. Sintela, a British seller of such technology, is mum on the specifics, but its system, branded Onyx, is used on America’s southern border. Tunnels can even be revealed by detecting tiny decreases in gravitational pull caused by their voids.