Iran: Tehran willing to retaliate, but being cautious

Tension between the U.S. and Iran is being ratcheted up on what seems like a daily basis. Mostafa Ahmadi-Roshan from the Natanz uranium enrichment plant was killed in a car bomb on Wednesday. Tehran has accused Israel of what they've called a "heinous act". Washington denied any role in the death. This incident is the latest in a series of mysterious incidents involving Iran's nuclear industry. Columnist and veteran war correspondent Eric Margolis believes Tehran is willing to retaliate, but is being cautious at the moment.