Read my post, I said Identify, not as you said in your post “Identity”. The word “Identify” is the challenge word to unknown incoming vehicles or persons.
You’re correct, the air traffic process is known as “Identification”.
Now that we’ve settled the semantics, do you have something relevant to add with your 35 years of FAA traffic control?
What is your theory?
Secondly, that IFF is used by EVERY air traffic facility in the world, not just military. The aircraft transponder is the airborne component of the 'IFF' system.
My theory? well, in addition to being a controller, I also ran an aviation consulting business for 25 years. I have read/studied literally thousands of accident reports, and been involved in a few investigations. There has been so much conflicting, erroneous, retracted and redacted, mis-reported, mis-analyzed, unattributed information that only a fool would say he had a good idea of what happened. And I ain't that fool. What a damned goat-rope.