Besides, why Iraq and not other countries in need... say, countries without large oil reserves?

No, you have it right.

SELF INTEREST.

Saddam applauded 9/11, was taking potshots at US planes, sponsored an assasination attempt of Bush Sr. in Kuwait, was upm to his eyeballs in corrupt transactions with Europe and Russia...and he had dabbled in WMD as recently as 1993.

That was FAR MORE than enough provocation for "regime change."

We sacrifice lives for returns constantly. We permit auto travel - even though it is enormously destructive in terms of yearly casualties and the environment. Why?

SELF INTEREST.

Cars, at this time, permit freedoms and a level of complexity to trade, commerce and social exchanges. We are willing to pay that price in lives - FAR more by many magnitudes than the casualties of the Iraq conflict.

We interfered in WWII in Europe twice, taking sides based upon...

SELF INTEREST.

England was one of our biggest trading partners and businesses didn't want Germany to have a monopoly the exporting of minerals and materials from the region.

Seeing things in a box without context, such as casualties, is no way to evaluate our choices on all sorts of matters. Every down side has a good side and vice-versa.

Context counts.