What ensued? This is not ancient history. Did the Palestinians begin building the state that is supposedly their great national aim? No. No roads, no industry, no courts, no civil society at all. The flourishing greenhouses that Israel left behind for the Palestinians were destroyed and abandoned. Instead, Gaza's Iranian-sponsored rulers have devoted all their resources to turning it into a terror base -- importing weapons, training terrorists, building tunnels with which to kidnap Israelis on the other side. And of course firing rockets unceasingly.

The grievance? It cannot be occupation, military control or settlers. They were all removed in September 2005. There's only one grievance and Hamas is open about it. Israel's very existence.

Nor does Hamas conceal its strategy. Provoke conflict. Wait for the inevitable civilian casualties. Bring down the world's opprobrium on Israel. Force it into an untenable cease-fire -- exactly as happened in Lebanon. Then, as in Lebanon, rearm, rebuild and mobilize for the next round. Perpetual war. Since its raison d'etre is the eradication of Israel, there are only two possible outcomes: the defeat of Hamas or the extinction of Israel.

Israel's only response is to try to do what it failed to do after the Gaza withdrawal. The unpardonable strategic error of its architect, Ariel Sharon, was not the withdrawal itself but the failure to immediately establish a deterrence regime under which no violence would be tolerated after the removal of any and all Israeli presence -- the ostensible justification for previous Palestinian attacks. Instead, Israel allowed unceasing rocket fire, implicitly acquiescing to a state of active war and indiscriminate terror.

Hamas' rejection of an extension of its often-violated six-month cease-fire (during which the rockets never stopped, just were less frequent) gave Israel a rare opportunity to establish the norm it should have insisted upon three years ago: no rockets, no mortar fire, no kidnapping, no acts of war. As the U.S. government has officially stated: a sustainable and enduring cease-fire.

If this fighting ends with anything less than that, Israel will have lost again. It can ill afford to lose any more wars.