Is it better for the prospect of peace if the U.S. and its adversaries all have large fleets of cheap warplanes or small fleets of expensive ones? I would argue that the F-35 is not only very expensive for the U.S., but has actually increased the cost of fielding fighter jets (as well as air defense systems) for the entire world. And therefore it has made it more expensive to fight a war for every country. Now ask yourself would you rather live in a world where the cost of wars is lower or higher?