Read the book. You’ll understand the technology. They’re secret weapons deriving from experiments that go back a hundred years. You’ve heard of Ludwig Prandtl? Oscar Schrenk?
https://www.amazon.com/Intercept-UFO-Renato-Vesco/dp/B0006WI572
I find it hard to credit the explanation of UFOs as all being ours. Granted, some are, but other aspects of the UFO phenomenon exceed that explanation. There are centuries of sightings before electricity was even in use, persistent reports of alien abductions, and UFO intrusions into military airspace and close surveillance of and interference with nuclear weapons.