Stealth drones with nuclear payload coordinated to detonate simultaneously

think about it

they could be pre-programmed to take off on triggering events

current tech could not detect them until too late unless every border was covered by very high speed detect and destroy batteries

p

black swan due but might never come

imagine the pope suddenly telling all Catholics that there is no God

:-)

p

Introducing Spot - coming to your village loaded with great new weapons