The points I'm willing to cede when discussing the U.S.'s / U.N.'s war in Iraq:
1 - If Bush, Cheney, and Rumsfeld were taken to trial as war criminals I wouldn't be opposed.
2 - The Bush administration's public rationale for going to war were mostly lies.
3 - As stated in the title, the war itself was horrifically executed by the West.
Given all that, I'd say that an argument could be made that there were legitimate reasons to remove Hussein from power, and that in the long view, waiting would have made the situation in the region worse than it is today.
Spot false dilemmas now, ask me how!
(If you're not on the edge, you're taking up too much room.)
What do you reckon those legitimate reasons to be? I think some points in particular bear consideration in regards of the effects of the war.
#1 - For the last 10 years, people in Iraq have been dying, and continue to die, at a higher rate than before; now, the deaths are more evenly distributed amongst sectarian groups. The Kurds in particular seem to do better, although they had already been shielded from much of the nastiness of the Hussein regime following the first Gulf War.
#2 - The country is unstable, and it's unclear if or when that might change. I'm not saying the stability that existed before was better, just that the country could still head in directions that are worse still than the situation today.
#3 - A counterweight to Iran has been removed. Iran today has influence in Iraq and elsewhere that it wouldn't have otherwise.
#4 - How would the Arab Spring have effected the country? It's impossible to estimate how entrenched Saddam Hussein would have been at the time, and what the population's mood would have been, so it's unclear whether an uprising might have been happened, and been successful if it had. On the other hand, one might consider what role the effects of the invasion might have on how the Arab Spring unfolded, and whether it would have happened then, or at all.