If you eliminate the “alien” possibility, it is pretty clear that these are man made and probably ours.
Other countries would have used them by now—at least Russia. And China would have been selling them.
The part that should piss people off is the energy source (which must be clean and compact) and the anti-grav tech that would revolutionize transportation.
But the concept that we have to have a tactical Trump card drives these people. And it’s a shame.
At no time in history has any nation that developed superior military technology failed to deploy it. The idea that we’ve had this tech since the 1940s and never implemented it is silly. Visual/radar sightings of these things have been going on that long. I just don’t buy that any nation that had this would sit on it for 80 years.