possibility that there could be some kind of terror attack here. and we know that the security situation on the ground has been a case of strange bedfellows with the united states and taliban trying to work to secure the various gates to this airport while the u.s. was completing this air lift. rob sanchez, you're in london. let's talk a little bit about the players on the ground here. because the threat here, unusually for americans who follow this war in afghanistan the last 20 years, wasn't from the taliban. they were effectively security partners now. there's been a lot of talk about isis-k, the isis affiliate in central asia. what do we know about that group and the concern that these allied intelligence agencies might have had about them trying to make a splash while the u.s. is still in afghanistan? >> reporter: yeah, garret. so isis-k is isis khorasan. khorasan refers to an area of central asia. this is the afghan affiliate of the islamic state.