While the US has gotten a lot better at counter-terrorism since 9/11, many bad guys are still out there — and the Taliban victory in Afghanistan has given them a huge morale boost. "They will see this as they did, indeed, the ISIS victories in Syria and Iraq, as a sign that they're on their way back," says former UK diplomat Rory Stewart. "Whatever we think about Afghanistan, nobody should be concluding that there are no terrorist threats." Watch his interview with Ian Bremmer on this episode of GZERO World.

Watch the episode: Is America Safer Since 9/11?