Please don't offer that tired stuff about 'undeclared wars' being exceptional as regards law; the US Congress has declared war exactly 5 times in history...but our various armed services have been committed to cause on more than 200 other occasions. And, the Supreme Court has upheld every single sentence incurred by such 'free speech' advocates under such circumstances, as well they should have done.
I don't know why some people want certain words to be used, especially since there was a condition given to the use of that force: Saddam had to disarm, and if he didn't we were going to war with him.
This is hardly the same as a "police action."
This is a declared war, no matter what anyone else thinks. But it was a war specifically against a regime, not a real "nation."