These are reasons, true enough. They do justify the action. However, as I said before, there were reasons out there and that was not the question. The question was, were those reasons enough to justify full scale war? The two you present here I would argue would not be enough to motivate the American public to get behind the action. When the UN failed to enforce its own resolutions, my reaction was "good, the UN is irrelevant and we should just get the heck out of it". As for failure to comply, we could have just initiated a bombing campaign on any site we suspected of having WMDs. After a while, there would either be no sites left or the inspectors would have been called in. I think most people were behind the war because of the post 9/11 reaction. We wanted those bastards (fill in the blank as to who those bastards might be) to pay.
My own reasons for backing the war are:
1. Saddam knew the rules and he broke them. He was warned of the consequences and could have stopped it at any time.
2. If we are going to prosecute a war on terror, Iraq is the perfect place to establish a foothold. Right next to Syria, Iran, and Saudi Arabia. Sort of like a safe spot in the hornets nest.
3. I have been reading of the atrocities in Iraq for years. From the chemical bombings in Halabja to the draining of the Marshes and the near irradication of the Marsh Arabs, and most of the horror in between. We could accomplish something good for those people while protecting our people.
Now those are MY opinions. I personally know the price of going to war, and I would not back a war that was frivolous and didn't have multiple benefits, the first being to the USA.