What Difference Would an Iran Deal Make? – Patrick Clawson and Mehdi Khalaji
(dailyalert.org, Nov. 27, 2014)

Negotiating a nuclear deal with Iran will only be the first part of resolving the nuclear impasse. At least as important will be persuading Iran to abide by the deal over time. In 2003-2004, Tehran reached two nuclear agreements with the EU3 and then walked away from them. In 2009, the regime reached a deal with the P5+1, but Supreme Leader Ali Khamenei vetoed it. (Washington Institute for Near East Policy)