Whilst we are on the subject.....
The overflights by "commercial " drones of such as , reported in France ,Nuclear sensitive sites is of concern.
We in the "West" no longer have the total monopoly on advanced technology.
Most of us are aware of "stealth" in the radar context , but there is a lot out there concerning optical stealth.
Indeed the first imagery of such a device could well be accidental and/or captured by a civilian who sees something "a bit odd" overhead. ( "Oh look, a UFO !" )
As far as I am aware no formalized effort has been put in to addressing this aspect of the problem.....