JERUSALEM

AHMED AL-JABARI — the strongman of Hamas, the head of its military wing, the man responsible for the abduction of the Israeli soldier Gilad Shalit — was assassinated on Wednesday by Israeli missiles.

Why? Israel’s government has declared that the aim of the current strikes against Gaza is to rebuild deterrence so that no rockets will be fired on Israel. Israel’s targeted killings of Hamas leaders in the past sent the Hamas leadership underground and prevented rocket attacks on Israel temporarily. According to Israeli leaders, deterrence will be achieved once again by targeting and killing military and political leaders in Gaza and hitting hard at Hamas’s military infrastructure. But this policy has never been effective in the long term, even when the founder and spiritual leader of Hamas, Sheik Ahmed Yassin, was killed by Israel. Hamas didn’t lay down its guns then, and it won’t stop firing rockets at Israel now without a cease-fire agreement.

When we were negotiating with Hamas to release Mr. Shalit, members of the Israeli team believed that Mr. Jabari wouldn’t make a deal because holding Mr. Shalit was a kind of “life insurance policy.” As long as Mr. Jabari held Mr. Shalit, Israelis believed, the Hamas leader knew he was safe. The Israeli government had a freer hand to kill Mr. Jabari after Mr. Shalit was released in October 2011. His insurance policy was linked to their assessment of the value of keeping him alive. This week, that policy expired.

I believe that Israel made a grave and irresponsible strategic error by deciding to kill Mr. Jabari. No, Mr. Jabari was not a man of peace; he didn’t believe in peace with Israel and refused to have any direct contact with Israeli leaders and even nonofficials like me. My indirect dealings with Mr. Jabari were handled through my Hamas counterpart, Ghazi Hamad, the deputy foreign minister of Hamas, who had received Mr. Jabari’s authorization to deal directly with me. Since Mr. Jabari took over the military wing of Hamas, the only Israeli who spoke with him directly was Mr. Shalit, who was escorted out of Gaza by Mr. Jabari himself. (It is important to recall that Mr. Jabari not only abducted Mr. Shalit, but he also kept him alive and ensured that he was cared for during his captivity.)