Growing up in the 1950s, in a time of Russian aggression, there was a saying: America would not be defeated by a foreign enemy, but will fall from within by its own people. It has taken me some 70 years, but I’m now very sad and concerned that this could happen to us. Bettmann // Getty ImagesWalter Cronkite | Saint Joseph, Mo. The level of divisiveness and fear among us is palpable.