Did you sleep through the Cold War?
hardly, but there was at least one big difference. there were only two nuclear powers and neither were so nuts as to want a war. not that it couldn't have happened, but rational people tend to act in more rational ways.
now we have irrational people with various WMD. some of them have end times views that would encourage them to use those weapons. some are just geneticaly nuts. the new super powers may or may not act in rational ways...we don't know yet. we also have economic instability in a way we have never seen. never before have economies been so intertwined and we really don't know what would happen if they were to begin to collapse. we have everything on computer. what happens if someone were to introduce something that did damage to the computers of major banking or investing? the grid is unstable. we don't know exactly how much might go down in a big solar storm.
we had defined problems and a defined enemy for the cold war. the same can't be said now. being well armed is a little cheap peace of mind.