Look at this City (1962)

Started in the summer of 1961, even before the Wall was built, the film becomes an explanation after this historical event as to why things can no longer go on as they were before. Unmistakably, as in almost all of Karl Gass' films, the passion with which he treats his subject is unmistakable. If you want to get to know the zeitgeist of the historically significant year 1961, which on both sides knew more the Cold War vocabulary than factual arguments, you can see the Eastern variant in this propaganda film.