I honestly think its all about money - not even oil. Wars are good for big business, do you really think BAE, EADS, Lockheed Martin, Boeing etc want the 'War On Terror' to end? When the Cold War ended the Military-Industrial complex was probably pretty concerned about profits. Not any more.
Right now, business is good, and all the dying is being done by somebody else. If the bosses of every major arms manufacturer and every senior politician,were told that they had to send a son or daughter out to the frontline by the end of October you'd soon see a change. How many senators or MPs have a son or daughter out there 'in harms way' right now? Somewhere around the zero mark? What about all the senior executives at BAEs, EADS, Lockheed Martin, Boeing etc. Do any of them have a son or daughter out there, or even worse - that's come back in a box, or with significant parts of their body or mind damaged beyound repair? What do you think?