American and European leaders say that there is no evidence that Iran is building a nuclear weapon.
Even Israel – which has threatened to attack Iran on its own – now admits the same thing.
As Haaretz noted on January 18th:
The intelligence assessment Israeli officials will present later this week to [Chairman of the Joint Chiefs of Staff Martin ] Dempsey indicates that Iran has not yet decided whether to make a nuclear bomb.
The Israeli view is that while Iran continues to improve its nuclear capabilities, it has not yet decided whether to translate these capabilities into a nuclear weapon – or, more specifically, a nuclear warhead mounted atop a missile. Nor is it clear when Iran might make such a decision.
http://www.washingtonsblog.com/2012/01/even-israel-admits-that-iran-has-not-decided-to-build-a-nuclear-bomb.html