"According to an Administration national security strategy document released on March 16, 2006, the United States 'may face no greater challenge from a single country than Iran.' To date, the Bush Administration has pursued several avenues to attempt to contain or end what it views as the potential threat posed by Iran, including pursuing limited engagement directly or through allies. However, support for a longer term policy of changing Iran's regime has apparently gained favor within the Administration as Iran has resisted permanent curbs on its nuclear program. In the nearer term, the Administration is intent on slowing or blunting Iran's nuclear program through diplomatic and economic pressure by the United Nations Security Council or a coalition of like-minded major countries. Because Iran continues to advance its nuclear program despite international criticism, some advocate military action against Iran's nuclear infrastructure. International concerns on nuclear issues and other strategic issues have been heightened by the threatening statements of Iran's new president, Mahmoud Ahmadinejad. Iran's nuclear program is not the only major U.S. concern on Iran. Successive administrations have pointed to the threat posed by Iran's policy in the Near East region, particularly material support to groups that use violence against the U.S.-led Middle East peace process, including Hizballah in Lebanon and the Palestinian groups Hamas and Palestinian Islamic Jihad."
CRS Report for Congress, RL32048