But I am also outraged. And in that anger, I find a glimmer of hope, a promise of a better future to come, though not without great pain, suffering and sacrifice first. What do Dhaka and Baghdad really have in common, except that radical groups have exploited years of failed governance, religious extremism and economic stagnation to establish a foothold?

Because the extremists don’t see anything but us — mainstream Islam — and them.

They’ve picked their sides, and they have their vision. Can the incomparably greater number of Muslims in the world who are so rightly horrified today come together with their own vision — which includes stamping out the extremists who seem to hate Islam, and Muslims, and the Prophet Mohammed, more than anyone else?

The Muslim world will have to work together in ways that seem hard to imagine right now. It’s true that, right now, we don’t have the institutions, the leaders, the visions, to make this happen. But we will have them. Because there is no opting out. The contest is existential.

Some Muslims shrug and say they’ve got nothing to do with it. But it — extremism — has something to do with them.