While current US policy is not working, we believe military action against Iran is a terrible option for the US, regional stability, and for Israel at the present time.

First of all, it is not clear that air strikes could actually cripple the Iranian nuclear program more than setting it back a few years - if a weapons program actually exists (per the 2007 NIE - link to PDF of report). If anything, it will further empower Iranian hardliners who believe the only way to safeguard their country would be to accelerate their pursuit of nuclear capability.

We cannot ignore how high the cost of an attack would be. American military strikes against Iran put our troops in Iraq and Afghanistan in the crosshairs of Iranian reprisals and will likely throw our ally Israel into bloody conflict with Hezbollah and Hamas, both of which receive support from Iran. Oil prices would sky rocket with world wide economic repercussions. Our Gulf allies would likely experience significant blowback from their citizens.

Next → What should we do about Iran? "Real Engagement and Smart Containment."