IR Diplomacy has “an interview”:http://www.irdiplomacy.ir/en/news/71/bodyView/1897871/Sanctions.Could.Not.Force.Iran.to.Negotiate.html with Peter Jenkins, who was UK Permanent Representative in Vienna from 2001 to 2006.
Without getting into his policy recommendations, he makes an interesting argument:
bq.. IRD: In June 2005, Bruno Pellaud, former IAEA Deputy Director General for Safeguards, said that if Iran had a military program, it would not have accepted the Additional Protocol. Is this a sound analysis?
PJ: Essentially, yes. *Iran would have been taking a big risk in December 2003, when it provisionally applied the Additional Protocol, if it had possessed nuclear material or facilities that it had no intention of declaring to the IAEA,* since the Additional Protocols grants the IAEA intrusive inspection rights.
p. Given that Iran apparently shelved its nuclear weapons program in late 2003 and Tehran agreed in October 2003 to accept the Additional Protocol, it might be more accurate to say that Iran decided to halt the program _because_ Tehran was going to be implementing the AP. But Jenkins makes an interesting point, nevertheless.
Note that the IAEA, while welcoming the NIE’s conclusion that there was no active nuclear weapons program in Iran post-2003, never endorsed the view that a nuclear weapons program existed prior to 2003 either:
“With respect to a recent media report, the IAEA reiterates that it has no concrete proof that there is or has been a nuclear weapon programme in Iran.”