Saturday marks Yom Kippur, the holiest day on the Jewish calendar and, this year, the 40th anniversary of the outbreak of the Yom Kippur War, the greatest trauma in Israeli history. On the morning of October 6, 1973—the day on which Yom Kippur fell that year—Chief of Staff David Elazar met with Prime Minister Golda Meir and Defense Minister Moshe Dayan to warn that the Egyptian and Syrian armies were about to attack Israel. Elazar urged a preemptive strike; six years earlier, in the Six-Day War, Israel’s preemptive strike had proved highly effective. But Meir and Dayan, who were under...