Thanks for the explanation.
~ Back then, and presumably now, every officer had a background check and a security clearance. It was either Secret, or Top Secret. I've forgotten. Very routine. Even I had such a clearance. (Never needed it.) But for any particular bit of info, you still had to have a need to know in order to see it. ~
Yep, don't know about the officers but I know in the enlisted ranks, you would be screened for a T/S if your job might come in contact with that info on a need-to-know basis. By changing AFSC (Air Force) the clearance might automatically drop a level if the need-to-know was no longer there, didn't mean that they were a security risk.
(unlike Kerry)