Permit me to further explore the point about how we ought not draw an artificial distinction between the U. S. invasion pre- and post-Saddam. This is the kind of thing that really gets me steamed–when people say that the point of the war was to make America safer by removing Saddam from power. I know I've said this several times before here, but you don't just remove a politician from power; you replace a politician. And just because you don't choose the replacement doesn't mean your target won't be replaced. You don't invade a country without intending to occupy it.
People who studied Iraq before the war (myself included) were wondering what kind of fantasy world the neo-conservatives were living in when they proclaimed that the US invasion would effect a Reverse Domino Theory of democracy. We were going to make Iraq a "free country" whether they were ready or not. What neo-conservatives worship is power; the idea is that proper, decisive use of that power can accomplish good only if we are not afraid to use it. This argument is not wrong in and of itself, but it's hard to imagine how to put their theory into practice without fucking it up somehow.
There is an irony here that would be delicious if it wasn't so damn tragic–Saddam Hussein was a proponent of the same theory. In fact, what separated Saddam's regime from the rest of the world was that he refused to accept the post-UN New World Order which said that you can't take territory by conquest anymore. In fact, protecting the territorial integrity of member states is the real raison-detre for the United Nations in the first place. National self-determination is the order of the day; nations can now break down into their components (e.g., Czechoslovakia's "Velvet Divorce") but very rarely since World War II does one nation engulf another in combat ("East Germany," I hear you cry, but I said "in combat." Nice try).
Saddam looked at history and rightly or wrongly called bullshit. He invaded Kuwait on several pretenses, but we know what's really involved; Saddam just never repudiated the right to territory by conquest. And neither do the neo-cons.
The real question is whether or not the use of force is going to achieve (at the very least) the self-stated goals of the forceful. In an international law system that recognizes the right to national self-determination over any other right (think about that), you really have to wonder if we can still use our military the we used to in the good ol' days of, say, World War II or the Grenada invasion.
How did we, as a nation, get from being inspired by the slogan "Live Free or Die" to merely offering it as a choice to an impoverished and unready people halfway around the world?
Speaking of the use of power, I think a major reason the war on Iraq was so popular was because we were feeling impotent. We needed to show we could kick some ass, and I mean "some ass," not necessarily a particular ass. Americans are used to being the most powerful country in the world; not just militarily, but culturally. And our supremacies in those categories are being challenged, which makes patriots nervous. Nervous enough to kill to make us feel better.