The US, and the allies to which it exports F-35s, are overwhelmingly a net force for peace in the world. There’s a reason why the phrase “Pax Americana” is so well-known. You can think of these as war machines, since they’re literally machines made for use in war — but you can also think of them as war prevention machines, causing would-be aggressors to think twice before, like, invading Singapore or some such unpleasantness.