I just read the former US UN rep John Bolton’s book Surrender is not An Option. He details quite devastatingly exactly how badly the Europeans were outmanuevered, outnegotiated, and outlasted by the Iranians.
To put it suffinctly, the negotiation process went like this:
From the book, the Europeans and Russians have pretty much acknowledged that the Iranians are pursuing nuclear weapons. The IAEA has actually edited out data that details how far along the Iranians are in the nuclear weapon process.
Anyways, damn good book and pretty much outlines how the current diplomacy process has not worked at all, a process that Barack Obama has been marking as the highlight of his foreign policy plans.