content: I have news for you. If there was a real war to break out between large manufacturing nations  autonomous mass produced drones would be immediately put into production and deployed in huge numbers and would dominate the airspace.  The only real defense against them is emp electromagnetic pulse weapons, gps destruction and large area explosive weapons like fuel air bombs or nukes to clear huge airspaces of drones. A few hidden factories could crank out an airforce of thousands of drones in weeks with no pilots needed.  As a comparision the largest standing airforces now only have thousands of planes and they all require personnel and supply lines.    In other words a few factories hidden away could crank out airforces equal to the united states airforce in weeks...especially if they have been stockpiling engines or implement 3d metal printing in mass. You can make radar proof aircraft out of ground up bamboo and glue using 3d printers and pulse jet engines which are little more than stamped exhaust pipes.   https://m.youtube.com/watch?v=2WjMTDIaJ3A  Bamboo can grow at 3 FEET a day in some climates.