From the Nov. 4, 2013 Congressional Research Service report, Iran: U.S. Concerns and Policy Responses.
A priority of Obama Administration policy has been to reduce the perceived threat posed by Iran to a broad range of U.S. interests. Well before Iran’s nuclear issue rose to the forefront of U.S. concerns about Iran in 2003, the United States had seen Iran’s support for regional militant groups, such as Lebanese Hezbollah, as efforts to undermine U.S. interests and allies.To implement U.S. policy, 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 for purely peaceful purposes.
Five rounds of multilateral talks with Iran in 2012 and 2013 yielded no breakthroughs but did explore a potential compromise under which Iran might cease producing medium-enriched uranium (20% Uranium-235—a level not technically far from weapons grade) in exchange for modest sanctions relief. International sanctions have harmed Iran’s economy, and the June 14, 2013, first round election victory of a relative moderate, Hassan Rouhani, appeared to reflect popular Iranian sentiment for a negotiated nuclear settlement that produces an easing of international sanctions.