Cover Story How big a threat are the world's jihadi groups?

Sophisticated and lethal, growing in number, Islamic State and other extremist groups won't become a global force. Here's why.

Raqqa Media Center of the Islamic State Group/AP

Mullah Abdul Rauf Khadim looked like any ubiquitous insurgent commander in southern Afghanistan. He had a sunbaked complexion, serried black beard, charcoal eyes, and the usual accessory – an AK-47 slung over his shoulder.