Because your rationalization of it is weak.

"It has to do with liberation, installing democracy and capitalism where none has existed"

These are sheepherders, traders in the market place and a culture living centuries behind us. They hadtheir marketplaces, their religion and their families. I twas THEIR way of life. Who are WE to change all that?

>"Preventing future 9/11's."

Your thinking is fairly primal, if not adolescent.
OUR "defense intelligence agencies" had plenty of warning of the possibility of these attacks, yet did NOTHING to stop the. Put th blame where it belongs.
Now we've had a wake-up call, and instead of being the gorilla crashing through the jungle scaring all the chimps, perhaps we'd be better off to sit watchfully in our lair and get the other chimps to work with us to turn their own gorillas in.....

>"And if somebody didn't stop Sadam Hussain, he would have likely caused more 9/11's or worse."

Well, looks like you bought that idea pretty well, and you could be right. Let's see if we find WMD AND Sadam.

>"If it comes down to seeing my child killed on a Sunny September morning or one of theirs...Well I'm sorry that they have choosen to put their children in the line of fire, I refuse to allow them to bring the fight to my children."

Boy, have YOU got a lot to learn. You still sound pretty young, and fairly naive.
Maybe still living near your birthplace, like the same state perhaps?
Sadam is nor our only worry, trust me......and now we've instilled an even bigger Jihad towards us.
Sorry, but your reasoning and flawed.
And I don't enjoy or condone ANY violence of any sort, unless it is for defense.

Nitwit.