... was something that came about at the snap of a finger and was widely publicized. It was part of a well-planned and well-orchestrated attempt at genocide that started with state sponsored racism and then grew worse and worse.
I think you meant 'wasn't something that came about...'
And yes, people did try to escape. Many did while they could (Albert Einstein was one.) And it wasn't always possible. You may wish to look up the S.S. St. Louis and what happened to to those people that tried but failed to escape.
Basically, Hitler's regime 'boiled the frog.' (Note: I'm not advocating doing this...it's just an illustrative story.) That is, if you put a frog in boiling water to start with, it will attempt to jump out. However, if you start the frog in cold water and slowly turn up the heat, it will not attempt to leave until it's too late. There were many quite reasonable people that could not conceive of what Hitler planned to do. Additionally, it wasn't just the Jewish people who suffered. Gypsy's, the disabled (physically and/or mentally), and pretty much anyone that didn't fit the 'perfect picture' of the Third Reich were systematically destroyed.
I definitely liked the way Sam handled his coming face to face with the woman and the fears that had become a permanent part of her psyche. What the people with those numbers endured was nothing short of pure unadulterated hell. I pray fervently that we never have a group that repeats those evils any where or any time.
As to the Cuban Missile Crisis, I did live through it as a child. I was about 5 years old and I remember both the TV special alerts and how people acted around me. My parents certainly didn't try to scare us but fear has a way of seeping out even when we think we're being bastions of serenity. I remember my brothers and I being much like the children on the show.
And yes...we saw the duck and cover films. Keep in mind that even in Hiroshima and Nagasaki, not everyone died even fairly close to ground zero. Many died within hours or days but some survived for years. The duck and cover scenario wouldn't have done much, but it may have helped a few people depending on the actual deployment of a bomb. Additionally, I've been at the Trinity bomb site and I saw how far the people who witnessed the detonation were which wasn't that far relatively speaking (a few miles) and all of them survived and many lived for years although there was a high rate of cancer deaths in the witnesses. There were towns not much further out (e.g. 30 miles) from the bomb that felt some effects but weren't destroyed or even seriously damaged. So, yeah, in the 1960's it was the best that could be done living in that insanity.
Also, there was a Twilight Zone episode that appeared in the 60's much closer to the threat. In it, a physician is having a birthday and all their friends (neighbors) are at the dinner. An alert comes across the air and the show is how all the neighbors react since the physician has a bomb shelter and none of the others do. The story has all sort of realities in it as the veneer of polite society disintegrates. I suggest you compare the two shows and perhaps some of Paul Brown's motivations could be seen. It's not an exact duplicate but some of the concepts are similar.
Oh..and as to the way Sam was treated, keep in mind this. Sam was being their uncle but all of the sudden he's not acting like their uncle always had in the past. Previously, the uncle probably agreed with his brother. Now, in the midst of all the crazyness that was affecting that community, he starts spouting what (as Bluedana pointed out) could be seen as treasonous words. He'd been going to college and many felt that many professors were secretly 'red.' So...his brother throwing his brother out could have been directly related to 'OMG...my brother's becoming one of them...' and as a father, he wants to protect his children from messages that were abysmal to him.
Anyways...that's how I see the show in various context's. Interesting thread.