IDF Chief of Staff Lt. Gen. Benny Gantz knew Friday afternoon, as he sent aircraft into the sky to kill Zuhair al-Qaissi, leader of the Popular Resistance Committees, that one million people would soon be tethered to their safe rooms, hundreds of thousands of children would miss school, buildings and infrastructure would be damaged, the local stock market would dip and, it would have seemed only reasonable, some lives would be lost.

He also knew that wars sometimes start with a single, hurried decision. Blood begets blood. Rockets could have reached Tel Aviv or its outskirts. Ground troops could have been called to the front. The politicians, once the ground troops were inserted, would have demanded a tangible achievement, something to go the polls with, and that, Gantz knew, would not be easily attained in the labyrinthine alleys of Gaza, where all changes seem to point in the same direction — increased extremism.

Yet when word reached him that al-Qaissi had gotten into his blue Opel along with another two combatants, meaning they were out in the open and verifiably not surrounded by family members or other civilians, he authorized the hit. Tuesday morning, speaking before new recruits to the Kfir Brigade, he explained why. “The planned terror attack in the south could have had strategic implications,” he said.

This is vague army talk for game-changing results and, based on previous experience with the PRC and the current situation in Sinai, likely meant a combination of two things: a defensive strike in Egypt, perhaps shedding Egyptian blood and damaging the ever-more brittle peace with our neighbor to the south; and the possibility of a kidnapping, either to Sinai or through the porous border to Gaza.

Both possibilities, in today’s reality in the Sinai, were all too likely.

The 25,000-square-mile peninsula, ruled by Israel from 1967 to 1982, is in the midst of fundamental change. Religion is on the rise among the avowedly Muslim but traditionally impious Bedouin, and the rule of law, ever since the Arab Spring, is on the wane. Ehud Yaari argued in a recent paper for the Washington Institute for Near East Policy that these two phenomena, coupled with Israel’s 2005 withdrawal from Gaza — which Israel hoped would lead to greater Egyptian involvement — have facilitated the unprecedented spread of Hamas political and religious ideology among the Bedouin tribes of the Sinai.

Yaari, an editorial board member of The Times of Israel and commentator for Channel 2 News, quoted a Bedouin blogger, Ashraf al-Anani, who depicted the effects of the withdrawal as “a fireball [that] started rolling into the peninsula.”

Hundreds of tunnels link the northern Sinai to Gaza. Terrorists send arms and operatives in both directions. In the past, the main flow of arms, according to intelligence reports, was from Iran by sea to Sudan and from there to Egypt, across the canal, into the rugged desert region – a haven for smugglers for millennia, and today home to a robust $300 million trade – and underground to Gaza. Over the past year, though, according to experts, much of the weaponry is being stored in Sinai, and terror operatives from Hamas and the PRC are taking the tunnel route in the opposite direction, from Gaza to the mountainous desert.

The Egyptian gas line to Israel has been attacked 10 times over the last year. Heavily armed Bedouin tribesmen have chased Egyptian security personnel from key positions. Rockets have been fired from Sinai to Aqaba and Eilat. But the lens through which Gantz was likely looking, when weighing the strike, was the August 18, 2011, attack.

The attack was led, if not necessarily executed by, the PRC, a Gaza-based, three-pronged organization founded at the start of the al-Aqsa Intifada in 2000. According to Yoni Fighel, a senior researcher at the the IDC’s Institute for Counter-Terrorism and former colonel who served in the IDF’s Intelligence Directorate, it is part of “a consortium of terror groups collectively known as Jaljalat, or rolling thunder.”

The Meir Amit Intelligence and Terrorism Information Center states that the original members were, ironically enough, disgruntled Fatah members who wanted to strike at Israel more openly. Today the organization is comprised of three wings, two of which cooperate with Hamas and are staffed by former Izz a-Din al-Qassam members who, like their Fatah forebears, resent their former organization’s newfound stateliness. The third is more closely affiliated with the global jihad organizations.

Their flag closely resembles Hezbollah’s and above the raised rifle are the words, from a Koranic Sura much beloved by extremists: “Kill them [the infidels] wherever ye shall find them.”

The IDF at first claimed that, in last August’s attack, members of the two Hamas-affiliated wings, under the command of Kamal a-Neirab, snuck out of Gaza and into Sinai and from there to Route 12, north of Eilat, where they sprung the ambush that claimed eight Israeli lives. Fighel, Yaari and other military and Middle East experts dispute that.

The identities of the terrorists were never revealed. Mourning tents were never assembled in Gaza. Rather it seems more likely that experts from Gaza sneaked into Sinai and readied the Bedouin for an attack of unprecedented severity.

“This was a hugely complex attack,” Fighel said. “They would have needed to be briefed, trained, and maybe run through a full model” of the plan. The 12 terrorists, dressed in Egyptian army uniforms, executed a terror attack that included gunfire, grenades, mines, suicide bombers, snipers and, according to Yaari, shoulder-held surface-to-air rockets that, for the first time, were fired at Israeli aircraft. Their goal, according to the Intelligence and Terrorism Information Center, an NGO run by and for Israeli intelligence veterans, was to kidnap an Israeli.

The quick arrival of a Golani Brigade force may have been the only thing that foiled their plans. But the deaths of several Egyptian officials led to a swell of anti-Israel sentiment, an Israeli apology and a near-lynching of security personnel in the Israeli Embassy in Cairo several weeks later.

Yaari calls the situation in the Sinai a “time bomb.” He too believes that the terrorists were aiming to kidnap an Israeli. Furthermore, friction along the border, he writes, does not often contain itself to Israel and the terrorist group within the neighboring state, but rather, as in Jordan and Lebanon, drags the state hosting the terror into the fray.

If looked at in that light, Gantz, who knew a targeted killing would trigger rocket fire on Israel and who remains uncertain that the killing has prevented a terror attack in the south, evidently felt he had little choice but to target Zuhair al-Qassi on Friday afternoon.