I always assumed during the run up to the war that the best evidence that the USA was sure that Iraq didn't actually have any significant WMDs would be if the USA and its diminutive chorus line invaded.

The claim that it was the other way round, and that the "intelligence" told them the WMDs were there, and they only found out the truth after the invasion seems extremely improbable to me.

The big worry is that this time it might be the other way round - once again they come up with "intelligence" assuring them that North Korea is a paper tiger, like Saddam's Iraq, but it turns out to be false.