This Congressional Research Service report discusses the U.S. concerns and policy responses to Iran. "The Bush Administration characterizes Iran as a 'profound threat to U.S. national security interests.' The Administration perception is generated primarily by Iran's nuclear program but is increasingly focused on Iran's military assistance to armed groups in Iraq, which is resulting in U.S. battlefield losses, as well as on Iranian aid to two groups that threaten U.S. allies in the Middle East -- the Palestinian group Hamas and Lebanese Hezbollah. The threat assessment of some other governments was lessened by the December 3, 2007 key judgements of a National Intelligence Estimate (NIE) that indicates that Iran is likely not on a drive to develop an actual nuclear weapon, but Administration officials say that this finding was not the main thrust of the NIE, which judged Iran to be continuing uranium enrichment. The Bush Administration approach to contain the potential threat posed by Iran's nuclear program is to strengthen international economic pressure on Iran while also offering Iran potential cooperation should it comply with international demands that it end its enrichment of uranium. Three U.N. resolutions (1737, 1747, and 1803) ban weapons of mass destruction (WMD)-related trade with Iran, freeze the assets of Iran's nuclear and related entities and personalities, prevent Iran from transferring arms outside Iran, ban or require reporting on international travel by named Iranians, call for inspections of some Iranian sea and airborne cargo shipments, and call for restrictions on dealings with some Iranian banks. Separate U.S. efforts, showing some success, have included trying to persuade European governments to curb trade, investment, and credits to Iran; and pressuring foreign banks not to do business with Iran. At the same time, there is increasing recognition in the Administration that sanctions alone have not compelled Iran to suspend uranium enrichment. In June 2008, the Administration and its partners presented an enhanced package of incentives that might encourage Iran to cooperate, but Administration skepticism that Iran would respond positively to inducements appears to have proved correct with Iran's apparent rejection of the plan."
CRS Report for Congress, RL32048