The White House has dismissed a suggestion from Iranian President Mahmoud Ahmadinejad that Iran would close its nuclear facilities as long as Western nations did the same. His comments came as a deadline set by the UN for Iran to freeze its uranium enrichment program expires today. Meanwhile Iran has accused the US of backing a bomb attack that killed 11 Revolutionary Guards, just one week after the US accused Iran of supplying bombs targeting US troops in Iraq. We speak with retired Air Force Colonel Sam Gardiner. [includes rush transcript]

Iranian President Mahmoud Ahmadinejad said Tuesday that Iran would close its nuclear facilities as long as Western nations did the same. His offer comes as a deadline set by the UN for Iran to freeze its uranium enrichment program expires today. Iran has maintained it is not seeking nuclear weapons, saying its program is for purely peaceful ends.

Ahmadinejad's comments come amid steadily increasing tension between Washington and Tehran. The US military has increased its presence in the region deploying a second aircraft carrier to the Persian Gulf. The White House has repeatedly denied any intention of attacking Iran but, according to a Monday night report by the BBC, the US military has drawn up contingency plans for massive air strikes against Iran. The plans call for attacks on Iran's nuclear sites, air bases, naval bases, missile facilities and command-and-control centers.

The U.S. government has already determined the two circumstances which would trigger just such an attack: One is evidence that Iran was developing a nuclear weapon and the second is a “high-casualty” attack against American forces in Iraq that could be traced directly to the leadership in Tehran. The Bush administration recently accused the top levels of the Iranian government of supplying sophisticated bombs to anti-U.S. forces in Iraq.

Meanwhile, the Iranian government is accusing the United States and Britain of being involved in an attack last week that killed 11 members of Iran’s Revolutionary Guard.

• Sam Gardiner. Retired Air Force Colonel. He has taught strategy and military operations at the National War College, Air War College and Naval War College.