The real story behind Operation Pillar of Defense in Gaza has not yet been investigated, but now that the explosions have stopped, we are obligated to delve into the truth. The decision to kill Hamas military chief Ahmed Jabari, which was the opening shot of the operation, was made even though he was involved in negotiations on signing a long-term cease-fire agreement.

A few hours before he was assassinated, he had received a draft of an agreement for a permanent cease-fire with Israel, and he was apparently expected to reply to it affirmatively. The indirect contacts with Jabari had taken place over the course of months via Hamas' deputy foreign minister, Ghazi Hamad, with the knowledge and consent of Defense Minister Ehud Barak.

These contacts with Hamas were conducted by Gershon Baskin, who served as an intermediary in the deal for the return of kidnapped soldier Gilad Shalit. Baskin had reported his progress toward a draft agreement to the members of a special committee appointed by Barak back in May, a panel that also included representatives of other government ministries.

In other words, our decision makers, including the defense minister and perhaps also Prime Minister Benjamin Netanyahu, knew about Jabari's role in advancing a permanent cease-fire agreement. Jabari was the strongman of the Gaza Strip - Israel's "subcontractor," as Haaretz editor-in-chief Aluf Benn characterized him - so Hamad submitted each draft prepared with Baskin to Jabari for approval.

Also party to the negotiations on a permanent cease-fire were Egyptian intelligence officials. Some of the meetings between Baskin and Hamad took place in Cairo. These Egyptian intelligence officials were in constant contact with Barak's envoys, so one would assume that in addition to Baskin, they too were informing Israel of their impressions of the progress in the talks on a draft agreement.

At no point in the negotiations between Baskin and Hamad was the former ever told to stop.

Moreover, about a week before Jabari's assassination, Israeli military officials asked permission from their commanders to meet with Baskin and get a briefing. This permission was denied.

Thus the decision to kill Jabari shows that our decision makers decided a cease-fire would be undesirable for Israel at this time, and that attacking Hamas would be preferable. It seems a view had developed that Israel needed to strengthen its deterrence against Hamas rather than reach agreement with it on a period of calm. In the view of the defense establishment and the prime and defense ministers' bureaus, a cease-fire agreement might have undermined Israel's deterrence and weakened its image of resolve. Bolstering its deterrence, in this view, would be achieved by killing Jabari, who was liable to respond affirmatively to the offer of a long-term cease-fire.

In this way, Israel's leaders killed three birds with one stone: They assassinated the man who had the power to make a deal with Israel; they took revenge on someone who had caused more than a few Israeli casualties; and they signaled to Hamas that communications with it will be conducted only through military force.

Quite aside from the fact that the results of Operation Pillar of Defense didn't meet the expectations of those who launched it, the decision makers must answer one important question: If they knew it was possible to reach a cease-fire agreement (whose provisions, incidentally, were better than those of the agreement reached after the operation ) without going to war, why did they assassinate Jabari, and thereby also assassinate the chances of achieving calm without shooting? Is it possible, heaven forbid, that Barak and Netanyahu feared the opportunity to conduct a military operation at the end of their government's term would elude them, and that's why they ordered Jabari's liquidation?

To keep us from suspecting their motives, the prime minister and defense minister must explain their considerations and decisions in the Jabari affair.