Iran warns U.S. to back off from Persian Gulf

Iran issued a warning to the U.S. Navy operating in the Persian Gulf. The White House responded by saying that Iran is lashing out because its economy is suffering under sanctions aimed at its nuclear program. CBS News correspondent David Martin looks into whether Iran can back up its tough talk.

Iran wrapped up 10 days of naval exercises by warning the U.S. not to send an aircraft carrier back into the Persian Gulf. It may sound like an empty threat, but it's also clever propaganda.

The U.S.S. Stennis left the Gulf last week headed for home and won't be back anytime soon, so Iran can claim the Stennis didn't dare return.

But two other carriers, the Lincoln and the Vinson, are on their way to the region, and one of them is already scheduled to take part in exercises inside the Gulf.

As they have in the past, the Iranians could harass the carrier with their go-fast boats as it transits the two-mile wide channel through the Strait of Hormuz. But their chances of stopping a carrier are close to zero.

Over the last 10 days, Iran showed off anti-ship missiles, submarines and hydrofoils to back up a claim they surely don't believe: That closing the Strait of Hormuz to supertankers, which carry one-fifth of the world's oil, would be "easier than drinking a glass of water."

Iran rejects U.S. warning on Hormuz
Iran warns U.S. to keep ship out of Gulf

But the over-the-top rhetoric makes countries stop and think what would happen to their economies if a vital chokepoint for Mideast oil became a war zone.

It's one of the few cards Iran has to play to discourage the rest of the world from enacting tougher economic sanctions against its nuclear program. Sanctions already in place are taking a toll on Iran's economy.

Tuesday's saber-rattling sent the price of oil up by nearly $4 a barrel, so the threats may be empty, but they are not meaningless.