. >> now john wohlstetter talks about the threat of nuclear weapons today and discusses what can be done to safeguard against the ultimate catastrophe. this is about an hour. >> good afternoon, ladies and gentlemen, and thank you for joining me today, although i don't have something cheery for you. i was thinking how to start this. wasn't as nice as the very fine english historian who must've been thinking the same thing to write something in today's "wall street journal" opinion page for me, and the title of it is, let's all prepare for the cataclysm. we all think of august as a month where everybody is at the beach, sort of chilling out and all that in this heavily political season, just enjoying life. and for those of us in washington, congress is in recess, which generally speaking means a lot of lobbyists leave town so there's a lot less traffic. it's a rather nice time. robbers wanted to bring us back to a little historical reality, so over the last century among the peaceful events that have occurred, in august of 1914 world war i began. on the last day of august 1939 hitler decid