Updated on November 25 at 9:39 a.m. ET
Once death tolls get above 50 or so, they become impossible to process. The attack Friday on the Rawdah mosque in Bir al-Abed, north Sinai, killed more than 300 people, with a combination of bombs and light weaponry. The attackers executed survivors and gunned down first responders. Imagine five separate Las Vegas attacks happening all at once from different angles, starting while the victims are at prayer.
No one has claimed responsibility. But no points should be awarded for guessing that the Islamic State is at fault. It has motive and opportunity. Its Sinai province was the site in October 2015 of the downing of Metrojet 9268 out of Sharm al-Sheikh, which killed 224 people, mostly Russian tourists. The local IS affiliate, Ansar Beit al-Maqdis, has killed Egyptian police and soldiers in north Sinai, mostly around Al-Arish town, at a steady rate for the last three years. Most of these assassinations get no coverage in the western press. But IS propaganda has featured tidy little photo montages of men on motorbikes accosting plainclothes officers, shooting them in the head, and harvesting their ID cards (sometimes blood-smeared) for proof of death.