Generation X isn't the only generation to have grown up fearing war. My parents tell of a time when they actually had bomb drills in their classrooms and films (shown to school children) that scared the wits out of them. Does Generation X (my generation, btw) recall "duck and cover"? No...but the Baby-Boomers do.
I think there's always been a time to fear since these bombs were created. I don't feel entirely safe no matter how many we have, or how few some other country has. I don't wanna know how many missiles are aimed at the U.S. right now. It probably wouldn't help me get to sleep at night.