"A priority of Obama Administration policy has been to reduce the perceived threat posed to a broad range of U.S. interests by Iran, in particular by Iran's advancing nuclear program. Well before the nuclear issue rose to the forefront of U.S. concerns about Iran, the United States had seen Iran's support for militant groups in the Middle East, Iraq, and Afghanistan as efforts to undermine U.S. interests and allies. U.S. officials also accuse Iran of actively helping Syria's leadership try to defeat the armed rebellion there. The Obama Administration has orchestrated broad international economic pressure on Iran to try to compel it to verifiably demonstrate to the international community that its nuclear program is peaceful. Three rounds of multilateral talks with Iran in 2012 yielded no breakthroughs but did explore a potential compromise under which Iran might cease enriching uranium to 20% purity (a level not technically far from weapons grade) in exchange for modest sanctions relief. Further high-level talks took place on February 26-27, 2013 and April 5-6, 2013, both in Almaty, Kazakhstan. No breakthroughs were achieved in Almaty. Iran's Supreme Leader has not taken up U.S. offers to engage in the direct bilateral talks that many experts believe are required to produce a breakthrough. And, there is an emerging consensus that international sanctions--although severely harming Iran's economy--have not pressured the regime to the point at which it is compelled to compromise."
CRS Report for Congress, RL32048