In April 1948, Deir Yassin was an Arab village of about a thousand residents. It was captured then by Jewish forces seeking to break the siege of Jerusalem during the war for Israel’s independence. Most of the fighting was done by the underground soldiers of the Irgun and Lehi, with assistance from the Haganah, the official fighting force of the Jewish establishment. A truck-mounted loudspeaker blaring a warning for residents to flee the village fell into a trench that had been dug by villagers. The result was a bloody house-to-house battle with a high death toll. That much everyone agrees...