Hamas's offensive tunnels should not be confused with the burrows it has dug under Gaza's border with Egypt to smuggle money, consumer goods and military equipment. The newly discovered structures have only one conceivable purpose: to launch attacks inside Israel. Three times in recent days, Hamas fighters emerged from the tunnels in the vicinity of Israeli civilian communities, which they clearly aimed to attack. The ­concrete-lined structures are stocked with materials, such as handcuffs and tranquilizers, that could be used on hostages. Other tunnels in northern Gaza are designed for the storage and firing of missiles at Israeli cities.

The resources devoted by Hamas to this project are staggering, particularly in view of Gaza's extreme poverty. By one Israeli account, the typical tunnel cost $1 million to build over the course of several years, using tons of concrete desperately needed for civilian housing. By design, many of the tunnels have entrances in the heavily populated Shijaiyah district, where the Israeli offensive has been concentrated. One was found underneath al-Wafa hospital, where Hamas also located a command post and stored weapons, according to Israeli officials.

Washington Post