This report discusses the developments in Iranian foreign policy, their involvement with terrorist organizations, the developments made with respect to weapons of mass destruction, and human rights concerns. It also details the Bush Administration's efforts to maintain the sanctions put in place by the Clinton Administration.

According to the Administration’s “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 the potential threat posed by Iran, including supporting a long-term policy of changing Iran’s regime. However, the near-term Administration drive to prevent any Iranian nuclear weapons breakthrough has brought diplomatic and economic strategies to the forefront of U.S. policy.

This report discusses the debate over U.S. policy toward Iran, much of which has centered on the nature of the current regime. Some experts believe that Iran, a country of almost 70 million people, is a threat to U.S. interests because hardliners in Iran’s regime dominate and set a policy direction intended to challenge U.S. influence and allies in the region. President Bush, in his January 29, 2002, State of the Union message, labeled Iran part of an “axis of evil” along with Iraq and North Korea.

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." The Bush Administration announced May 31, 2006, that it would negotiate with Iran in concert with U.S. allies. If diplomacy and sanctions do not succeed, some advocate military action against Iran's nuclear infrastructure rather than acquiescence to a nuclear-armed Iran. U.S. concerns regarding Iran include Iran's nuclear program, Iran's influence on Iraq by way of providing arms and other material assistance to Shiite Islamist militias, and Iran's human rights practices, which include strict limits on free expression and repression of ethnic and religious minorities.

Iran's influence over the post-Saddam government in Iraq is substantial because the predominant parties in that government have long enjoyed Tehran's sponsorship. An emerging concern is that Iran's influence has extended to support for militant groups in Iraq. U.S. officials say that sophisticated explosive devices are entering Iraq from Iran, suggesting that Iran, or factions within Iran, are backing Iraqi factions that use violence to oppose the U.S. presence in Iraq.

This report discusses the reasons that Iran is considered a threat to U.S. security, including Iran's nuclear program, involvement with terrorist organizations, and involvement with neighboring countries' local governments. The report also discusses ways which the U.S. hopes to modify Iran's behavior with sanctions, and the effectiveness of these sanctions.

This report discusses the relationship between Iraq and Iran in the post-Saddam Hussein era, with particular focus on what Iran's intentions and/or long-term goals may be for increasing its influence in Iraq. The report explores the various strategies that Iran has used to spread its influence throughout Iraq's military and political spheres. The report also addresses the United States' concern over the Iran-Iraq relationship, especially as it concerns armed Shiite factions and U.S. efforts to stabilize Iraq.

This report describes Iran's known nuclear sites listed in official International Atomic Energy Agency (IAEA) reports and includes a map with the location of the nuclear facilities. For further information and analysis of Iran's nuclear programs, see CRS Report RS21592, Iran's Nuclear Program: Recent Developments, by Sharon Squassoni; and CRS Report RL32048 Iran: U.S. Concerns and Policy Responses, by Kenneth Katzman.