The recent wave of terrorism in Israel was touched off by two attacks linked to Islamic State (IS). Until now, notes Cole Bunzel, such attacks have been exceedingly rare, largely because IS “is not ideologically disposed” to focus its military efforts on the Jewish state. Bunzel sketches the objectives and attitudes of key IS leaders and concludes that, while the terrorist group may occasionally execute one-off strikes against Israel, it is unlikely to devote serious resources to it.

To understand how Islamic State views Israel, it is helpful to begin with the relevant statements of Abu Musab al-Zarqawi (d. 2006), the Jordanian founder of al-Qaeda in Iraq whose ideas form the foundation stone of the present-day caliphate. Palestine was not a prominent theme in al-Zarqawi’s speeches and lectures. Nor was attacking the Israelis a priority for him. On several occasions, he claimed that the liberation of Palestine would come only after victory had been achieved in Iraq and the Shiites had been subdued.

It was his view . . . that before one could effectively fight the “original unbelievers,” meaning the Jews and the Christians, it was first necessary to fight the Shiites. In this he was guided by his reading of medieval Islamic history, in particular the late Crusader period coinciding with rise of Salah al-Din al-Ayyubi (aka Saladin) and his defeat of the Shiite Fatimid caliphate in Egypt. In 1171, Saladin abolished the Fatimid caliphate and went on to construct a Sunni state spanning Egypt and Syria. A decade and a half later, in 1187, he captured Jerusalem following the decisive Battle of Hattin against the Crusader forces.

As Zarqawi saw it, there was “an important lesson” to be gleaned from this history. This was that “there will not be victory over the original unbelievers except after fighting the apostate unbelievers who are allied with the original believers.”

Concluded in 1979, the Israeli-Egyptian peace treaty ended nearly 30 years of intermittent warfare, and proved one of the most enduring and beneficial products of Middle East diplomacy. But Egypt may not have been upholding its end of the bargain, write Jonathan Schanzer and Mariam Wahba:

Article III, subsection two of the peace agreement’s preamble explicitly requires both parties “to ensure that that acts or threats of belligerency, hostility, or violence do not originate from and are not committed from within its territory.” This clause also mandates both parties to hold accountable any perpetrators of such acts.

Recent Israeli operations along the Philadelphi Corridor, the narrow strip of land bordering Egypt and Gaza, have uncovered multiple tunnels and access points used by Hamas—some in plain sight of Egyptian guard towers. While it could be argued that Egypt has lacked the capacity to tackle this problem, it is equally plausible that it lacks the will. Either way, it’s a serious problem.

Was Egypt motivated by money, amidst a steep and protracted economic decline in recent years? Did Cairo get paid off by Hamas, or its wealthy patron, Qatar? Did the Iranians play a role? Was Egypt threatened with violence and unrest by the Sinai’s Bedouin Union of Tribes, who are the primary profiteers of smuggling, if it did not allow the tunnels to operate? Or did the Sisi regime take part in this operation because of an ideological hatred of Israel?