What's the deal with the Iraq War?

I know a lot of people are supporting the troops, but what's the use if we could just send the troops home and let the Iraqi people build back their lives? The reason this war started was to make sure Iraq didn't have deadly weapons. No weapons were found. Then, the excuse turned to spreading democracy and terminating Saddam Hussein. Saddam is long gone and the war 'rages on'. People are dying everyday, Americans and Iraqis and others in between. And the U.S. is losing money everyday. And what about the discrimination between races and religions and cultures? Weren't the United States established to provide peace for those seeking better life?