The moment Nadav Peretz began to lose hope was when he finally got through to the emergency helpline. The Hamas militants embarking on what would become the deadliest ever attack on Israeli territory had burst into his kibbutz, or communal village, of Nahal Oz. Peretz and his partner had been hiding in the safe room of their house for hours, desperately trying to call in help from Israel’s security forces. “I was begging [the woman who answered my call] ‘send the army, send them’,” Peretz recalls. “And she told me: ‘We know, we’ll be there.’ And then she must have...