The value of the US in Iraq made really, really simple.
US in Iraq:
Gas $3.45 a gallon.
US out of Iraq:
Gas $9.75 a gallon.
Apply to the US economy and do the math.
This isn't about Iraqis anymore, it's about securing our access and the stability of a supply of oil after the Arab world proved anti-US & unstable on 9/11/2001.
;-)
