What U.S. hopes to achieve by striking Iran-backed militias

The U.S. is responding to last weekend’s drone strike in Jordan that killed three U.S. troops with airstrikes against Iran-backed militias in the Middle East. Pentagon officials say it took just 30 minutes for B-1 bombers and other U.S. aircraft to hit more than 85 targets in Iraq and Syria. Joe Buccino, a retired U.S. Army colonel, joins John Yang to discuss the strikes.