Want less war? #Cryptocurrency solves this. When they can't print the money out of thin air, they'd have to pass a war tax. No one would vote for it. Peace.
P.S. While the money is printed out of thin air, its value is actually stolen from the citizens through inflated prices.
P.P.S. The effect on the world of a government stealing its citizens savings through inflation; to buy a war, is perhaps worse than what a counterfeiter does with their ill-gotten loot.