I think everyone involved in aviation should be ‘shadowed’ by someone from a security service.
Pilots, engineers, cabin staff, ground handlers - all under constant surveillance by someone from a security service. You cannot put a price on aviation security. (Let’s not speculate on what we should do about the aviation security service personnel - we’ll just assume that the clearance process places them unquestionably above suspicion.)
After all: If we change the way we live our lives to deal with the terrorist risk, the terrorists have won!