Man, motives are irrelevant. The end result of the Iraq war should have been, in human terms: "-1 massmurdering idiot intent on invading other countries." The end result is now obscured with the equation: "-100K Iraqis dead." So you can see what went wrong, in humane terms, in that war, the rest is irrelevant, and you can see all mistakes from there. Roughly, nobody cares about whether the guy was murdering people with WMDs or kitchen knifes -so the UN presentation was a cock-up,- everybody (now) cares about oil, or other, motives -which could have been avoided with some clear statements,- nobody knows whether US got out of Iraq too early, too late, or just in time, since the "-100K Iraqis" is an awful statistic.
The oil motives, the geographical motives, Israel, the strategic alliance motives, nobody really cares about it long term. The only thing people most people in the world will care about is the humane equation and why that conflict ended with that equation which will spring all mentioned other 'inhumane' motives. And it is all irrelevant, since the only thing which matters is the humane equation.
(Btw, the above is not meant as a critique on the US.)