Description:Iran's army commander said the U.S. had moved the John C Stennis aircraft carrier out of the Gulf because of Iranian military exercises. But Tehran's warning of 'action' if the ship returns. Iran has responded to tighter U.S. and European Union sanctions over its nuclear programme with increasingly belligerent rhetoric. But the threat of action takes that rhetoric to a new level. It's already spooked oil markets last month by saying it could stop shipping through the Strait of Hormuz. (1:17)