How precisely does this rise above the level of sheer idle speculation? The CIA asserts the intelligence is faulty, Blair insists it's genuine but cannot be shared, so someone simply decides it cannot be shared because the French are withholding permission. Where's the substance?
"...so someone simply decides it cannot be shared because the French are withholding permission. Where's the substance?" Italian intelligence, the reported source of the forged documents, has asserted that they got them from the French.
Ever since the forgery has become known, the speculative source has been France. They had opportunity. And they had motive -- to cover their continued game of footsie with Saddam...and to embarrass the USA.
It's not "substance". But it seems a well-founded guess...