Iraq War - Is Just

Now my mind is on Iraq war again as have just come through a debate on it. Whether the intention of the Bush's administration was to destroy Iraq (for no reason other than just to destroy), the invasion did free the Iraqi from Saddam regime which the Iraqi people themselves were trying to bring down.
It's unfortunate to the ordinary people that their leaders couldn't unite the nation but armed their men and started infighting and worse they brought outsiders to spoil the situation. If they fought but not only for the sake of fighting but also for reconciliation, they could have shortened the war and the suffering period of the people. Actually, politics is rather difficult and no conflicts around the world ended easily even thought there was such a war known as seven-day-war(?).
Actual death toll killed by the Americans and the actual death toll killed by the infighting and terrorism can be compared and should be. Whence the Americans tried to solved the problems and invested billion after billion, the world was silent as they couldn't take the burdens onto their shoulders - of course this made the US image uglier.
I'm only trying to emphasize what I see in this war.
Understandably it is just for the Americans to say how they don't want to bare the burdens that the entire world has been trying to avoid. I don't blame the world because they have no chance to involve and solve this crisis as the Iraqi leaders are not actually ready to stop the conflict all together but enjoying the backing of confronting sides - the west and the terrorism backed by a few nations.
Consider where do the funding on terrorisms come from? How can without actual fundings, the terrorists afford such expensive activities?
Well, it's OK if one wants to say 'they are not terrorists but resistant groups'. If they are really resisting the Americans and the invaders, then why can't they negotiate on the table to make the American out? Why have they needed to kill the Iraqi people as well?
Both Sonni and Shiite are Iraqis and they should come together to a debate without violence. Then many lives and moneys can be saved.