Israel blowing a PR opportunity again

There have been at least 6 terror attacks against Gaza crossings in recent weeks, that have killed an injured Israeli soldiers and civilians, the most recent being a foiled attempts Monday night. (I don't think that number includes the mortar attacks that the crossings constantly come under.) Jimmy Carter's pals in Hamas have claimed responsibility for some of them. And yet, Israel today has opened two of these same crossings: Israel has opened the Erez and Sufa border crossings into the Gaza Strip Tuesday morning. 86 trucks of supplies are expected to be transferred to the Palestinians through the Sufa crossing throughout Tuesday. The trucks will contain basic food supplies such as fruits and vegetables, meat products, fish, flour and sugar. Diapers and medicine will also be transferred. The Erez border crossing will be opened for sick Palestinians who require medical treatment to cross into Israel. Why does Israel consider itself obliged to supply those who want to see it destroyed? Moreover, why does Israel continue to provide targets for those who actively use Israel's humanitarian desires as a weapon to kill Jews? Wouldn't it make sense at the very least for Israel to announce that every crossing that gets attacked will be automatically, immediately closed for two weeks or a month? Just announcing it ahead of time, and following through, would at least force the world to look at the phenomenon of Arab terrorists purposefully placing their own people at risk. By announcing these rules ahead of time, the onus for protecting Arab civilians goes from Israel to the Arab leaders of Gaza in the court of public opinion, and Hamas would be forced to explain to its own people why killing Jews is more important than their own food and medicine. Hamas apologists would be on the defensive. Is this really so difficult?