Funny thing about guns . . . . . . they rarely smoke unless someone has pulled the trigger recently.
It seems that the "smoking gun" metaphor is particularly inapt for this set of circumstances. Perhaps looking for a gunbarrel with powder residue from a long-past firing would be a more appropriate way to paint the picture. But then, again, we all knew that Hussein did all those evil things way back when.
The only value to creating the image of an immediate threat is to justify a war that is, in the Administration's view, a necessary precondition to re-establishing a formal western (spell that: US) presence in the Middle East (other than Israel) for any of a number of purposes; strategic advantage, oil, political stability, oil, revenge, oil.