Well... Classified documents tend to remain classified. The concern is that releasing any documents or evidence which result from covert operations gives the outside world some idea of the mechanisms we're using to uncover that evidence. I'm guessing that what they have was obtained via channels that the government would rather not bring to light. I honestly doubt there's any fabricating of evidence here. I am sure Iraq is doing enough bad things under the covers that we don't ened to go around fabricating evidence... But I still don't think military options are, at this point, the answer.