Of course we were involved in this. The mission training was done in the Arizona desert, we had assets in the region, and B52s in the air “training” at the same time.
Plus we gave them IFF codes.
So they used the same code of the day as we were. The transponders must be switched off after everybody knows each other. The swept freq, power, pulses, wavelengths that are ECM would blind the transponder anyway. Only a handful of people know what the code is. This was a successful operation. I give it five ***** for secrecy.