Basically, either Hussein was incompetent or he was trying to play a game of brinkmanship with the international community that he lost. Whether or not his actions justified invasion by the us is debatable (I do not believe so). Also the us repeatedly blatantly misrepresented Hussein to paint him as collaborating with "terrorists". but the fact is he did have wmd.
"There's no doubt Iraq hasn't fully complied with its disarmament obligations as set forth by the Security Council in its resolution. But on the other hand, since 1998 Iraq has been fundamentally disarmed: 90-95% of Iraq's weapons of mass destruction capacity has been verifiably eliminated ... We have to remember that this missing 5-10% doesn't necessarily constitute a threat ... It constitutes bits and pieces of a weapons program which in its totality doesn't amount to much, but which is still prohibited ... We can't give Iraq a clean bill of health, therefore we can't close the book on their weapons of mass destruction. But simultaneously, we can't reasonably talk about Iraqi non-compliance as representing a de-facto retention of a prohibited capacity worthy of war"
Also, just checking the news updates and it appears that the President did not clear this strike with congress, but instead informed the Russian authorities about his intentions before issuing the order. Is there any more clarification on this?