This is an especially superficial take, sure the Constitution says nothing about national security but reality sure does...

Any person that has ever gotten a security clearance has given up some of their first amendment rights to do it and if they talk about the wrong thing to the wrong person they will absolutely go to jail.

And as always the classic example of free speech being limited still stands. Go yell FIRE in a crowded movie and see how your dumbass 1st amendment argument keeps you out of jail.