Conservative Congressman Mike Waltz (R-FL) explains why he fears that a full US troop withdrawal from Afghanistan will create a power vacuum in Kabul, leading to chaos, destruction, and a national security threat for the US that will eventually require troops to be sent back in. Waltz, a former Green Beret who served multiple combat tours in Afghanistan and elsewhere, shares his concerns in a conversation with Ian Bremmer on GZERO World. He warns, "One of the things I don't know that everyone realizes is when the military goes, those contractors will go, the CIA, our eyes and ears on the ground will go." The interview on GZERO World airs on US public television starting Friday, April 23. Check local listings.

Watch the GZERO World with Ian Bremmer episode.