That's rather naive. You conveniently forget the fact that before you shoot down an F-35, first you have to spot it. Not to mention that building a drone with

That's rather naive. You conveniently forget the fact that before you shoot down an F-35, first you have to spot it. Not to mention that building a drone with capabilities similar to a manned fighter is a very hard problem and you can be quite sure that US's rivals (China, Russia) are decades away from fielding one.