"The Bush Administration has pursued several avenues to attempt to contain the potential strategic threat posed by Iran, at times pursuing limited engagement with Iran and at other times leaning toward attempting to change its regime. However, some experts believe a potential crisis is looming over Iran's nuclear program because the Bush Administration is skeptical that efforts by several European allies to prevent a nuclear breakout by Iran will succeed. U.S. sanctions currently in effect ban or strictly limit U.S. trade, aid, and investment in Iran and penalize foreign firms that invest in Iran's energy sector, but unilateral U.S. sanctions do not appear to have significantly slowed Iran's WMD programs to date. Some advocate military actions against Iran's nuclear infrastructure, but others believe that a combination of diplomatic and economic rewards and punishment are the only viable options on the nuclear issue."
CRS Report for Congress, RL32048