Good question, better answer

Exactly why is the U.S. deployed in Iraq, according to you?

Fine.

Let's stop mincing words.

We're in Iraq because Muslims have stated over and over and over that their only goal is to kill all non-Muslims.

After 9/11, we started taking them at their word, and since we didn't want to be killed, our only choice was to start killing Muslims before they killed us.

Iraq had Muslims in it, so it was as good a place to start as any. In fact, better than most, because it was in the heart of Muslim country, and having troops there gives us a credible force-projection threat throughout the entire putrid, corrupt, murderous Muslim region. It's easier to kill Muslims in other countries from Iraq than it is from Kuwait.

And now Muslims have two choices:

They can reform their vicious, degenerate religion so that it allows for peaceful co-existence with other religions and - after embracing this enlightened, live-and-let-live philosophy whole-heartedly - they can become productive members of the civilized world, much like post-WWII Germany and Japan.

OR

They can be exterminated like vermin.

All the rest of this junk about WMD's, and mass graves, and liberation, and oil fields, and insurgents is just so much political window-dressing. America is fighting for its life against an insidious, deadly ideology. The people who cling to that sick, 7th-century belief system must either change their minds or be killed.

I wish with all my heart that we had enough manpower to conquer every last Muslim nation on earth and root this virus out once and for all, but we don't. So we'll start in Iraq, dragging these barbarians kicking and screaming into the 21st century. After that, hopefully the rest of the Muslim world will get the point. If not, there will be further examples, nation by nation, until they do.

Then, when the Muslim world is either civilized or dead, the war will be over.

I hope that answers your question.