Also, human life probably seemed relatively cheap, after a war where 10s of millions had just died and civilian targets had been firebombed. They probably just

Also, human life probably seemed relatively cheap, after a war where 10s of millions had just died and civilian targets had been firebombed. They probably just didn't get as worked up over threats that might kill someone in a few decades, when they had become used to the prospect of being killed at any moment.