I'd say it's likely that we're still protecting the identity of a mole in Saddam's regime, and for good reason. The reason is so we can do this kind of operation again in the future. It's a tough job being the Prez; that's why we have a tough man in that job right now.
Notice how you never hear a word from the MSM that Iraq probably was involved in a terrorist attack against the US before the invasion (besides the first WTC attack that we know was sponsored by Iraq). We may have learned about this from an informant in Saddam's regime or through some high-tech communication intercepts. Now if Clinton had invaded Iraq, do you think we would have heard about likely Iraqi involvement in terrorism against the US, even if Clinton decided to keep this information classified? I think we would have heard a lot about it from the MSM and Dems in congress. But with Bush in the WH, you hear absolute silence.