Personally, I fail to see how that would be (except for stock holders of arms companies etc). Surely the American state would save a ton of money by having their army shrunk by 1/3.
Population control? Is the US worried about there being too dense population of arabs in the world? I don't think that's true - and not for when they waged war in Korea or Vietnam either.
Seems to me war is only good for absolutely nothing.