"There is broad international support for imposing progressively strict economic sanctions on Iran to try to compel it to verifiably confine its nuclear program to purely peaceful uses. Many U.S. and international officials appear to agree that the sanctions have not, to date, hurt Iran's economy to the point at which the core Western goals on Iran's nuclear program can be accomplished. Nuclear talks in December 2010 and in January 2011 made virtually no progress, suggesting that Iran's leaders did not feel sufficiently pressured by sanctions to offer major concessions to obtain a nuclear deal. However, in September 2011 Iran stated interest in new proposals that could form the basis of revived talks, a development that could change that assessment. The United States and its allies appear to agree that sanctions are an effective tool that should continue to be used to weaken Iran's energy sector and isolate Iran from the international financial system. [...] In light of U.S. revelations in October 2011 of a purported Iranian plot to assassinate the Saudi Ambassador to the United States, some are calling for additional U.S. and international sanctions."
CRS Report for Congress, RS20871