Please, can you shut up about the "I" word. I'm sick to death of it, and you've both made you're views known elsewhere. It's nothing to do "Should we go to war". I see no reason why this thread should end up locked just because, yet again, you've hijacked it.
As to the point about why the U.S.A. feels differently, it's because it has a different track record to the U.K.
The defining points for the U.S.A. were the results they achieved in Germany and Japan after WWII, where they moved into what hostile defeated countries and imposed their rule. The result has been, as they see it, flourishing friendly democracies. They see no reason why they cannot achieve the same result in Iraq.
And, possibly, they may be right. The reconstruction of a conquered nation may be a more applicable guide than that of winning a "hearts and minds" campaign against a guerilla force. And if they managed it with the Japanese mind-set of 1945, I can't see any intrinsic reason they can't do it in Iraq now.