Look, its a nice idea, but let me break it down for you quickly: peace is already profitable. Otherwise daily life would not be possible in countries such as New Zealand where the military makes up basically none of our budget.
However, war is far more profitable. It can easily bring in resources and other such things, force innovation, and increase one area of morale for a country.
So yes, many of our species problems would be solved if we decided to go with the less effiecient but also less pain inducing way.