There is nothing righteous or noble about the US suddenly needing to do something about Saddam.
It has far more to do with George Bush Jnr suddenly discovering that he hasn't the faintest idea how to run the US so like all pathetic leaders in history who find themselves embarrassed and in a hole he needs a diversion - better make it a big one overseas ...lots of things going seriously wrong at home.
Enter (re-enter Saddam as enemy No1 stage right..)
