- - Thursday, March 15, 2012

JERUSALEM — Israel’s lethal airstrike on a Palestinian militant leader in the Gaza Strip last Friday was a strategic reaction to changes brought about by the Arab Spring.

In the past year, militants in Gaza have established logistical footholds in the Sinai Peninsula in Egypt — taking advantage of weakened security by Cairo in the sometimes chaotic aftermath of longtime President Hosni Mubarak’s ouster.

Knowing Israel will not strike in Egyptian territory, militants have launched attacks from the Sinai against the Jewish state. Eight Israelis were killed in such an attack in August.

Israel’s assault in the Gaza Strip last Friday killed Palestinian militant leader Zahir Kaisi, who, Israeli officials said, was planning to carry out a similar attack against Israelis in coming days.

The Israeli airstrike spawned a four-day exchange of Palestinian rockets fired by the Islamic Jihad militant group and Israel’s counter-attacks, resulting in at least 24 Palestinian deaths and no Israeli casualties.

Hamas, which rules the Gaza Strip, did not participate in this week’s rocketing.

The flare-up of hostilities broke months of relative calm in Gaza in recent months, and has allowed Israel to establish new ground rules for deterrence by showing it will strike pre-emptively in Gaza before militants can conduct attacks from the Sinai.

Islamic Jihad, which fired hundreds of rockets, has threatened to use its long-range rockets capable of hitting the Tel Aviv the next time Israel engages in a targeted assassination.

Meanwhile, Israel is building a 140-mile-long fence along its border with the Sinai. The 15-foot-high barrier, equipped with sensors, is expected to be completed in about a year.