"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.' That perception continues, generated primarily by Iran's nuclear program and intensified by Iran's military assistance to armed groups in Iraq and Afghanistan and to Lebanese Hezbollah. In part to direct regional attention to that view but also to engage Iran on an Iraq solution, the Administration attended regional conferences on Iraq on March 10, 2007, and May 3-4, 2007, both attended by Iran (and Syria), and subsequently held bilateral meetings with Iran in Baghdad on May 28 and July 24, agreeing in the latter meeting to form a working group on Iraq security issues, which met for the first time on August 6. The Bush Administration is pursuing several approaches to attempt to contain the potential threat posed by Iran, but the U.S. emphasis is now on multilateral economic sanctions on Iran. Iran has not complied with repeated U.N. Security Council deadlines since August 2006 to cease uranium enrichment. […] To strengthen its diplomacy, the Administration has added components to efforts to contain Iran, including a consistent large naval presence in the Persian Gulf; arrests of Iranian agents in Iraq. The Administration strongly denies it is planning on military action against Iran, but has refused to rule it out."
CRS Report for Congress, RL32048