Donald Rumsfeld, during his resignation press conference, called the Iraq war misunderstood. Let me see explain it as I see it and see if he's right
First, this wasn't a "war" politically in that Congress never declared a war as required by the U.S. Constitution. Sure there was an "authorization for the use of force" but I don't see that as a documented power of the Congress.
Second, this was not an invasion since we never left Iraq after the first, world supported, invasion in the 90s to kick Iraqi troops out of Kuwait.
Okay, now on the the war understanding...
We overthrew the dictator based government of Iraq. The head of that government was Saddam Hussein, who ruled ruthlessly by most accounts. Under Hussein's rule there was generally peace between the disparate groups of Iraq. Saddam kept order under the threat of death, he put people in prisons and abused them.
This dictator had no weapons of significance with which to defend against the US overthrow action and had absoloutly nothing to do with the September 11th attacks. Despite the overwhelming volume of the "they have W.M.Ds" claims, there were many intelligent and knowledgeable people stating plainly that there was no way Iraq had any significant weapons or the ability to produce them.
We took down the Iraqi government with a minimum of troops to do so, thus eliminating the single stabilizing force in that country. We replaced that government with a U.S. chosen group of "leaders". That government and the U.S. Military put people in prison and abused them while not restraining the internal hatred of Iraq's citizens.
We stayed to help rebuild Iraq so the people could have the things we destroyed during nearly 15 years of constant bombing, demolition and shooting. Again, we never left Iraq, we flew daily raids in to the country bombing radar and suspected military installations. The thing the U.S. Military goes out of the way to ignore or deny is that we have bombarded Iraq with nuclear waste. The U.S. takes nuclear waste that would otherwise be buried miles underground for millennia and put it in to bullets and bombs. We then fired those weapons in to the population centers of Iraq.
Instead of actually rebuilding the infrastructure for the Iraqi people and cleaning up the radioactive waste, we spent billions of dollars sending vending machines to the military camps so our troops could buy a Snickers bar after coming back from a 2am raid on a civilian home.
The disparate factions of the country/region started fighting each other, catching thousands of civilians in the cross fire. These warring factions then decide to sometimes unite to instead attack Americans. We decide to label these people fighting against themselves and us as "terrorists", fueling even more the divisive nature of the occupation.
So the "war" was a pointless and poorly planned overthrow of the one person capable of keeping peace in the country during which the majority of the Iraqi people have come to be at least indifferent if not hostile toward our presence in their home.
As for that whole "war crimes" thing that Hussein was found guilty of... Let's then posthumously convict Winston Churchill of the same thing since he gladly supported the gassing of the Suni and Kurd villiages if they didn't pay their taxes on time; this obviously during one of Britain's failed attempts at occupying and transforming Iraq.
Does that about sum it up Mr. Rumsfeld?