Well according to my dad, they’re staged there. The triggers are somewhere else (dunno) but since they’re pretty big devices it’s easier to store them there and fly in the triggers or something like that; in any case he says the triggers are not installed.
A B61 is not big at all, maybe 1000 lbs.
What they have is a permissive action link. There is a somewhat complicated procedure to unlock the weapon. It must be followed exactly. Any attempt to override it renders the weapon useless. Details are very classified.
The Soviet Golf class sub that sank off of Hawaii may have been due to an attempt at a rogue launch. Their version of a PAL took out the sub. Brute force? Risk a thermonuclear war by rogue personnel or lose a sub. It’s logical. Remember the Cuban Missile Crisis could have been worse if Castro and Guevara carried out their plan to arm and launch the missiles - a plan that made Khrushchev crap his pants.