Whither the Smoking Gun?

Lean Left has this commentary regarding the State of the Union Address last night.

"We knew he wasn't really going to try and make the case for war with Iraq, although I find it disturbing that he repeated the false information about the aluminum pipes, and asserted that Saddam was helping Al-Queda without real proof."

Just one short question - we have not seen real proof that Iraq has or is aiding Al Queda, yet the administration continually asserts that it is so. We want to see real proof, but we are not allowed to.

What if that proof is such that its revealing would endanger the lives or families of the intelligence-gatherers themselves, or endanger their continuing intelligence gathering? What if there is an operative, or operatives, so close to either party that if we revealed the source of the information would put their lives or missions in jeopardy? Wouldn't that make you hesitant to say, "We have discovered proof that Hussein and Bin Laden are in cahoots, because Joe Schmoe CIA (or just "an operative") was able to bring us such and such documents, and photos, and tape recordings..."

Upon public announcement of the this proof, it might contain sufficient damning information that TPTB over there figure out who it is and...eliminate the mole.