Sorry for the ubiquity (word?)
Greed for oil, opium, means of production, gold or whatever commodity you may choose to fill in are the underlying reasons for most wars. As you pointed out, the reason we were there and not in Uganda is most probably the oil. My major point could be summarized as the "end justifies the mean".
Step back for a minute, Doug. If you look beyond the tragedy of the war itself, the US has no goals of subjecting the Iraqi or Afghani people to tyranny (except the tyranny of being one of our trading "partners"). Groups like Amnesty are not decrying "why we went into Iraq" but rather, "why are we not going to the other places where tyrants exists". A point I share and a point that has had me donating to this group for nearly 15 years. It's a subtle distinction, but very important to me.
The whole debate about "justification" is just an extension of the "am I my brother's keeper" argument. Strange, considering who it's coming from in this country (largely politically motivated Democrats). But if not the U.S., then who? Most countries have demonstrated a willingness to not give a rat's ass what happens in other countries so long as their own oil supplies, food supplies, and general well being are not threatened. Live and let die... That's the "moral high ground" position. :-)
I posted a few links in order to point out that tyrants left unchecked or "appeased" rarely turn out "good"... YMMV.
Just a few thoughts,
Screamer
But take your time, think a lot,
Why, think of everything you've got.
For you will still be here tomorrow, but your dreams may not.
Y. Islam - Father and Son