Israel thinks Iran is months away from a bomb and wants to strike now.
According the the NYT, we have convinced Israel Iran is more like a year away.
This is based on our intelligence gathering and analysis.
What possible reason would anyone have to do anything one way or another based on our intel... including us?
We were surprised by the Russian H-bomb.
We played chicken in Cuba while convinced that the missiles were not yet operational... but they were. (Probably added to our "mad bomber" cred... Our toughness in the face of nuking DC being a button-push away gave Kruschev something to think about.)
We thought Iraq did not have a nuke program when it did.
Then we told the world Iraq had a nuke program when it didn't.
Pakistan and North Korea both seemed to have tested nukes before we thought they could. (IIRC)
Who will have a bomb and when has not been a strong suit in intel from the jump.
But we will see a war or not based on it.
http://www.nytimes.com/2010/08/20/world/middleeast/20policy.html?_r=1&ref=todayspaper