Atemporary cease-fire in Gaza that simply allows Hamas to obtain more lethal weapons will assure a repetition of Hamas' win-win tactic of firing rockets at Israeli civilians while using Palestinian civilians as human shields.

The best example of Hamas' double war crime tactic was Tuesday, when it succeeded in sending a rocket to a town less than 20 miles south of Tel Aviv and injuring a child. At the same time, it provoked Israel to attack a United Nations school from which Hamas was launching its rockets. Residents of the neighborhood said two Hamas fighters were in the area at the time, and the Israeli military said they had been killed, according to the New York Times.

The Hamas tactic of firing rockets from schools, hospitals and mosques dates back to 2005, when Israel ended its occupation of Gaza. Several months ago, the head of the Israeli air force showed me a videotape (now available on YouTube) of a Hamas terrorist deliberately moving his rocket launcher to the front of a U.N. school, firing a rocket and then running away, no doubt hoping that Israel would then respond by attacking the rocket launcher and thus killing Palestinian children in the school.

This is the Hamas dual strategy: to kill and injure as many Israeli civilians as possible by firing rockets indiscriminately at Israeli civilian targets, and to provoke Israel to kill as many Palestinian civilians as possible to garner world sympathy.

Lest there be any doubt about this, recall the recent case of Nizar Rayan, the Hamas terrorist and commander killed in Gaza by an Israeli missile strike Jan. 1. Israeli authorities had warned him that he was a legitimate military target, as was his home, which was a storage site for rockets. This is the same man who in 2001 sent one of his sons on a suicide mission to blow himself up at a Jewish settlement in Gaza. Rayan had the option of moving his family to a safe area. Instead, his four wives and children remained with him and became martyrs as Israel targeted his home for destruction.

Hamas leaders have echoed the mantra of Hassan Nasrallah, the leader of Hezbollah, that "we are going to win because they love life and we love death."

It is difficult to fight an enemy that loves death in a world that loves life. The world tends to think emotionally rather than rationally when it is shown dead women and children who are deliberately placed in harm's way by Hamas. Instead of asking who was really to blame for these civilian deaths, people place responsibility on those who fired the fatal shots.

Consider a related situation: An armed bank robber kills several tellers and takes a customer hostage. Hiding behind his human shield, the robber continues to kill civilians. A police officer, trying to prevent further killings, shoots at the robber but accidentally kills the hostage. Who is guilty of murder? Not the police officer who fired the fatal shot but the bank robber who fired from behind the human shield.

The international law of war, likewise, makes it a war crime to use human shields in the way Hamas does. It also makes it a war crime for Hamas to target Israeli civilians with anti-personnel rockets loaded with ball bearings and shrapnel designed to kill as many civilians as possible.

In Lebanon in 2006, Hezbollah used this same tactic in its war with Israel, setting up civilians to be in harm's way of Israeli responses to rocket fire. When Israel accidentally killed civilians, Hezbollah celebrated them as martyrs. Similarly, the Hamas leadership quietly celebrates the deaths they provoke by causing Israel to fire at its rocket launchers, treating the dead Palestinian civilians as martyrs. The New York Times reported Friday that a wounded fighter was smiling at the suffering of civilians, saying "they should be happy" because they "lost their loved ones as martyrs."

The best proof of Hamas' media strategy of manipulating sympathy is the way it dealt with a rocket it fired the day before Israel's airstrikes began. The rocket fell short of its target in Israel and landed in Gaza, killing two young Palestinian girls. Hamas, which exercises total control of Gaza, censored any video coverage of those deaths. Although there were print reports, no one saw pictures of these two dead Palestinian children because they were killed by Palestinian rockets rather than by Israeli rockets. Hamas knows that pictures are more powerful than words. That is probably why Israel has -- mistakenly in my view -- kept foreign journalists from entering the war zone.

Israel must continue to try to stop the Hamas rockets that endanger more than a million Israeli civilians. It also must continue to do everything in its power to avoid Palestinian civilian casualties, not only because that is the right thing to do but because every Palestinian death plays into the hands of Hamas' leaders.

A bad day for Hamas is a day in which its rockets fail to kill or injure any Israeli civilians and Israel kills no Palestinian civilians. That is what Israel and the world must strive for. Hamas knows that the moment it ends its policy of firing rockets at Israeli civilians from behind the shield of Palestinian civilians, Israel will end its military activities in Gaza. That is precisely the result Hamas does not want to achieve.

Alan M. Dershowitz is a professor of law at Harvard University. He is the author of many books, including, most recently, "The Case Against Israel's Enemies."