It will probably take 20 years before we really know if it was really worth it or not.
If a democratic and peaceful middle east emerges from all this it will have been worth it. If not, well...
We have not had a peaceful Middle East in a very long time. Adding all that valuable oil into the mix in more modern times is certainly not contributing to the peace process. At best, we can buy some time. The rising power of the Islamic Shiite Persians however could potentially set the entire region off. We had the chance to stop Iran when the price was low, the peace at all costs Progressos however stopped that and GWB basically allowed it to happen. Now the price the Free World will pay to Stop Iran could potentially end up being catastrophic.