Who is blowing up Egypt? Thursday's car bombing in Cairo, which destroyed a national security force building and injured dozens, will be just a blip on the international headlines. But the bombing, along with a string of similar attacks, matters existentially in Egypt, where it's the latest episode in a mounting campaign since the army deposed elected president Mohammed Morsi in a coup d'etat two years ago.
The answer, so far at least, isn't what you might expect — or what Abdel Fattah al-Sisi's government would have you believe. There's little evidence that the attacks are coming from the Muslim Brotherhood, the now-outlawed party of the former president. Instead they seem mostly to be coming from far more radical jihadi forces based in the Sinai desert, who have recently been identifying themselves with Islamic State. Indeed, Islamic State claimed responsibility for the latest attack.
The Egyptian state is, on the surface, an unlikely target for the group. Organized Islamic State movements have so far focused on places plagued by power vacuums, from Syria and western Iraq, the organization's heartland, to would-be affiliates in Libya and Afghanistan.