I remember a time when you could just walk into an airport and board a plane. In fact bring along a guest to see you off, they will be told when to depart if they don't have a ticket.
Then along came the first hijackers and you had to go through security and have a valid ticket to board a plane. After 9-11 security ratcheted up even more and the guards became federal employees.
Now if a third class nation is getting to ready to launch a missile all the planes sit until receiving a green light. When does the next hyperloop leave SF for Tokyo?