> Still I expect US intelligence would know all the side effects of this weapon and not have to struggle identifying it, I expect they tested it 50 years ago already
You seem to be assuming US intelligence is as scarily competent as it is in the movies.
For instance even if they did test something similar 50 years ago, in the real world, all the people with that expertise would have retired long ago. To put it in perspective (with an imperfect analogy): 50 years ago, software engineers were writing code in COBOL and IBM 360 assembler, how quickly would a senior Java developer be able to parachute in and figure out and fix a subtle bug in an application written with those technologies?
Yes, it makes sense if such old stuff was experimented with in secret but then not used for decades.
But since we are entertaining conspiracies, what if US also is using this weapon, then they won't want to admit it and give clues on how to prove it was used.
My opinion(very uninformed) is that it is more probable that if a device is involved then it is some kind of spying/scanning tool and not a weapon.
You seem to be assuming US intelligence is as scarily competent as it is in the movies.
For instance even if they did test something similar 50 years ago, in the real world, all the people with that expertise would have retired long ago. To put it in perspective (with an imperfect analogy): 50 years ago, software engineers were writing code in COBOL and IBM 360 assembler, how quickly would a senior Java developer be able to parachute in and figure out and fix a subtle bug in an application written with those technologies?