Throughout, Israelis never abandoned the vision of peace. Still, we came to understand that the cause of the conflict was not borders or even refugees but the same hatred of Jewish statehood that drove the Arabs to invade us in 1948. We understood that our enemies required periodic reminders of the prohibitive price they would pay for murdering our families. We also understood that defending ourselves incurred economic, diplomatic and human costs, yet there was no practical or moral alternative. The tactic is deterrence. Our strategy is survival.

Negotiations leading to peace can be realistic with an adversary who shares that goal. But Hamas, whose covenant calls for the slaughter of Jews worldwide, is striving not to join peace talks, but to prevent them. It rejects Israel’s existence, refuses to eschew terror, and disavows all previous Israeli-Palestinian agreements — the terms established by the United States and the other members of the so-called quartet of Middle East peacemakers for participation in the peace process. Bound by its genocidal theology and crude anti-Semitism, Hamas cannot be induced to make peace. But it can be deterred from war.

This was the case with Hezbollah in Lebanon. Like Hamas, Hezbollah is an Islamist organization committed to Israel’s demise. It, too, ambushed Israeli soldiers on our side of the border and rained rockets on Israeli towns. Then, in 2006, Israel struck back, destroying much of Hezbollah’s military infrastructure, neutralizing its long-range missiles, and killing hundreds of terrorists. Hezbollah internalized the message, and since then its missiles have remained inert. The people of northern Israel, meanwhile, have enjoyed six of their quietest years ever.

This does not mean that the tactics of deterrence and the strategy of survival cannot result in peace. Egypt and Jordan tried more than once to defeat Israel militarily, only to recognize the permanence of the Jewish state and to sign peace accords with it. Similarly, the Palestine Liberation Organization, guided by nationalism rather than militant theology, realized it could gain more by talking with Israel than by battling us. The result was the 1993 Oslo Accords, the foundation for what we still hope will be a two-state solution. By establishing deterrence, Israel led these rational actors toward peace.

Unfortunately, Hamas is not rational. It targets Israeli civilians while hiding behind its own. During a campaign of murder and kidnapping in 2006 and 2007, it gunned down members of its rival, Al Fatah, in the streets. Its covenant says Christians and Jews “must desist from struggling against Islam over sovereignty in this region”; under its rule, militants firebombed a Christian bookshop. It celebrated 9/11 and mourned the death of Osama bin Laden. We hope some day to persuade its leaders to make peace with us, but until then we must convince them of the exorbitant price of aggression.