IMHO, he's a man with wounded integrity who was ill-used by the assbags in power.  He lied for them before the UN and the world, for which I'm sure he feels very, very sullied (as well he should).  That, at least, had a quasi-defensible motive (in Powell's mind): to bring down an awful tyrant whom he'd opposed for over a decade.

But this, an unmistakable case of political vengeance, this seems beyond the pale for Powell.  There was no other way to interpret it or parse it or rationalize it.  No one could possibly delude themselves into thinking the Plame leak was anything less than public punishment and intimidation.

I really don't want to think Powell would knowingly sink that far.