Thus when Saeed Jalili, Iran’s chief negotiator, claimed this week that Iran was “looking positively” at the West’s attempts to resolve the nuclear saga, his words should be taken with an enormous pinch of salt. Last time the Iranians made such promises, at Geneva in 2010, diplomats from the “P5+1” — the permanent members of the United Nations Security Council plus Germany — left the conference room in the confident belief that they had struck a deal to resolve the controversy over Iran’s nuclear ambitions. The deal specified that Iran would freeze its uranium enrichment programme, which most intelligence officials are convinced is part of a clandestine plan to build an atom bomb. In return the West would ease sanctions that have crippled the Iranian economy.