Because there was an investigation in progress and unlike the ENEMEDIA and the anti-American leakers in our government, the Bush administration follows the rules...no commenting on matters that are under investigation!
IMO, this entire outrage was a set up to discredit President's administration. Think about it:
Okay, I've wasted far too much time on this already.
The truth will set you free! Months before any investigation they had the opportunity to set the record straight and even point out the rogue cell at the CIA.
You and I both know George Tenet was called on the carpet in the Oval Office within a couple of days and explained this whole deal. Instead of attacking, the Whitehouse team retracted the famous "16 words" despite the Brits supporting their intel... This is why "Bush Lied" is almost written in stone now.
The troops deserved to have their mission defended better than this. Bush also deserved to be better defended. He is like his Dad in many ways.