Protocol is to visually identify the target. In the case of an airliner, they try to make visual contact with the pilots if they don’t respond by radio. There a

Protocol is to visually identify the target. In the case of an airliner, they try to make visual contact with the pilots if they don’t respond by radio. There are visual verification methods commercial pilots are trained on. And airliners have transponders and flight plans. If a civilian plane stopped talking to ATC, the Air Force is likely already involved. Additionally, we’re not on a high-alert war footing like during the Cold War. As far as I know, we don’t have hostile military aircraft routinely flying with transponders off on our coasts. Even if we did, I’m pretty sure the larger military radar systems that would be used to track this stuff can read transponders and separate out which plane is which.