The war made defense contractors rich, and drove up the price of oil, which continues to this day to make oil companies rich. The Bush administration had strong ties to defense contractors and the oil industry. Dots = connected.
Total world oil production has been decreasing since 2005, despite all the good news you hear. With the Iraqi production, the curve is going down but is nearly flat. That lead to oil prices of $100/barrel not going down. It hasn't gone up due to wars in the middle east, sadly. I realize people keep bringing that up, but it's not true. A few spikes, yes, the actual rise, no.
Without Iraq that would have been 2.5-3 mbbl/day less, or a 3.5% drop instead of a 0.3% drop.
I seem to remember from my economics class that oil demand is very inelastic. So if a 0.3% drop in supply leads to a price doubling/tripling (depending on the basis for that), what would a 3.5% drop have done ?
So while I do not pretend to know the intentions of America, I'm scared to think what would have happened without it. If oil was the target, the war was a success (for the world as a whole, America only really profited by not seeing the world go down), and lack of success would have meant total disaster. The timing was near-perfect as well.
But fact is, the only thing the Iraq war brought was a delay, or 2-3, maybe 5 years. The US shale boom is another maybe 5 year delay. Given that we're very close to the end of the second delay, we need to come up with something quick. Unless of course you'd like to see Russia take outright control of Western Europe, and have more middle eastern resource wars.
I blame conservatives for this too. They laughed for 50 years at all the hippies and eggheads who talked about the need for alternative energy. One of Reagan's first acts was to take the solar panels off the White House.