The issue of consequences is a loaded one. There is supposedly a Chinese proverb:

"It's a false economy to go to bed early to save on candles if the result is twins."

Was Nazism a consequence of the loss of Varus' troops in the Teutoburger forests during the reign of Augustus? Is that even a valid question beyond getting a paper done towards a degree?

Whatever the consequences in the Middle East, who is going to judge what comes out of the American incursion and what was inevitable in either case? History is not a science. Sometimes it's nothing but a polemic.

I believe the U.S. went into Iraq for more than one reason, but far and away the main and determining one was the likelihood that Hussein was making himself the master (and potential disburser) of WMDs. After 9/11 this is perceived by the U.S. as a direct threat.

The good of the Iraqi people is a potential and hopeful side benefit (and justification).