We have at least one generation that loves having electronics and the Internet listening for any word they say in their house, and they will kick into action.  
We are already far along on designing aircraft with A I  to defeat any human operated fighter.
Drones can be programmed to go anywhere and do anything.
It only takes one person to accidentally or deliberately use AI as a weapon and then we all die. 
We only have survived because we're smarter than everything else on this planet.
That’s about to change.