From Simon Tisdall in The Guardian:

Like riverboat gamblers casting loaded dice, Iran’s leaders have played a double game of deceit, duplicity and Persian blind man’s bluff in on-off talks with western countries since the existence of suspect nuclear facilities was first exposed. Now it seems the Iranian regime has been caught red-handed, and clean out of trumps, by the forced disclosure that it is building, if not already operating, a second, secret uranium processing plant.
The revelation will bring a triumphal roar of “told you so!” from Bush era neoconservatives in the US to hawkish rightwingers in Israel. The likes of former vice-president Dick Cheney and UN envoy John Bolton, and the current Israeli leader, Binyamin Netanyahu, have long insisted that Tehran’s word could not be trusted.
Yet the argument about who was right and who was wrong about Iran is hardly important at this juncture. Today’s disclosures have significant, real-time policy-shifting implications for those who must deal with the ever more believable claims that Iran is seeking nuclear weapons capability.
Britain has already changed tack. Foreign Office diplomats have been saying privately for months that bigger sticks would be needed this autumn, given Tehran’s endless foot-dragging. What they knew, but could not say, about its clandestine activities is now in the public domain.

More here.