As the old adage has it, all politics is local. That might seem a quaint idea in an age of social media and global connectivity. And yet, as a study co-led by an MIT political scientist finds, it may describe Middle East politics more accurately than many people realize. More specifically, sectarian identity in the Muslim world — especially the split between the Shia and Sunni sects of Islam — is often described as a transnational matter, in which people understand themselves as being part of a large divide spanning…
