http://www.bbc.com/news/world-middle-east-30015464
"Six world powers - the US, the UK, France, Germany, Russia and China - are seeking to persuade Iran to reduce its uranium enrichment to a level below that required to build a weapon."
Maybe they should add to this:
"The six world powers believe that the US should be free to, at some future point, invade Iran without the possibility of any nuclear retaliation. Hence it would be advisable to discourage Iran from acquiring a nuclear weapon. Intelligence sources reveal that in a private communication Iran is reported to have asked whether they really could be so thick."
Iran has been threatened with invasion multiple times. Isn't it just natural that they would want to build a nuclear bomb?