"The Obama Administration has adopted the long-standing assessment of Iran as a 'profound threat to U.S. national security interests.' This threat perception is generated not only by Iran's nuclear program but also by its military assistance to armed groups in Iraq and Afghanistan, to the Palestinian group Hamas, and to Lebanese Hezbollah. In its first year, the Obama Administration altered the previous U.S. approach by expanding direct diplomatic engagement with Iran's government and by offering Iran's leaders an alternative vision of closer integration with and acceptance by the West. To try to convince Iranian leaders of peaceful U.S. intent, the Obama Administration downplayed discussion of potential U.S. military action against Iranian nuclear facilities and repeatedly insisted that it did not seek to change Iran's regime. It held to this position even at the height of the protests by the domestic opposition 'Green movement' that emerged following Iran's June 12, 2009, presidential election."
CRS Report for Congress, RL32048