I had fools telling me this evening that Iran just wants nukes for protection and won't use them. And these were Republicans!
But think about it. If Bill Clinton or John Kerry or Al Gore were in power right now, the USA would be quaking in our boots and wondering how to appease Iran and to appease their masters in Russia. Putin was making a bet that he could stir up a little (or a lot) of chaos in the Middle East with very little risk. Now with America's strong response in Iraq, there is ample precedent for direct action by the US or by Israel, or both, against Iran before this threat becomes operational.
Should that happen, Russia will be in a bind, either having to defend Iran (WW3), or admitting that they've been caught with their hand in the cookie jar--and looking weaker, and more foolish, than ever.