They come down to a lot more than oil .
In an op/ed published in USA Today, Wes Clark briefly defined what he means by US interests as "dissuading Iran from pursuing nuclear weapons and its hegemonic aspirations, providing security assurances for the rapidly developing Arab Gulf states and working with our friends in the Middle East to ensure access to oil resources and regional stability."
So yeah, oil is a part of it, but only a very small part. Israel isn't mentioned at all, except maybe under the umbrella of regional stability, altho I know Clark believes that solving the Israel/Palestinian conflict is vital to combatting terrorism in the long run.
But what he's really getting at, seems to me, is that we cannot afford to allow the region as a whole to descend into bloody multi-national war. Not just the civil war that's within Iraq now, bad as it is. But regional war. With genocide. And eventually, almost inevitably, a nuclear exchange. THOSE are the interests he's talking about.
Ask yourself, what effects would a war like that in the Middle East, and possibly other Muslim nations, have on the US and our prosperity? Maybe even our lives? Do you really think we could or would sit back and let them kill each other off, or that only the ground from Israel to Iran would glow in the dark and no where else?
Traditionally, US interests over the long term have always included promoting peace, regional stability, economic development, and humanitarianism. Granted these haven't always been the first priority, and some administrations have put more emphasis on other things (especially back in the day when we were confronting the Soviets) but even most Republicans have at least paid lip-service to more lofty goals.
It's not about altruism, altho that's a factor. It's about what impact these things have on progress in general, on the competition between states, and more recently on the drive to proliferate more advanced weapons and the missiles to deliver them.
