On May 26, 1967, the Egyptian president, Gamal Abdel Nasser, issued the following statement about a war he planned to start: “The battle will be a general one and our basic objective will be to destroy Israel.” Nasser and other Arab leaders believed that the annihilation of the Jewish state was both certain and imminent. Several days later, the leader of the Palestine Liberation Organization, Ahmed al-Shuqayri, said, “We shall destroy Israel and its inhabitants and as for the survivors—if there are any—the boats are ready to deport them.” When he was asked about the fate of native-born Jews, he said, “Whoever survives will stay in Palestine, but in my opinion no one will remain alive.”

A short while later, on June 5, the Israeli government, believing the sincerity of these threats, launched a preemptive attack on Egypt and Syria, destroying their air forces on the ground. Six days later, Israel had gained possession of the West Bank, East Jerusalem, the Golan Heights, the Gaza Strip, and the Sinai Peninsula.

One would think that Yahya Sinwar, until recently the leader of Hamas in Gaza, had absorbed the lessons of 1967.