It is hard to imagine now how different the 1950s world of Soviet nuclear scientists was to that in the West. Here’s Roald Sagdeev, prominent physicist:

Everyone at the time was more excited by the prospects of going to the heart of atomic physics: the nuclear centers. Such installations were called “mailboxes.” They were so highly classified that they were not given intelligible names that had anything to do with the real substance of their work. Entering this kind of physics had an enormous number of advantages. We knew, for instance, that the system in charge of such militarized sciences was the most powerful and rich in the country. In addition to higher salaries, employees would also benefit from special food stores and medical treatment. Furthermore, such institutions were surrounded by an aura, an atmosphere of enhanced respect in the country. There was a general feeling of pride in working for the military-industrial complex. … We had praise for people doing such jobs. Pacifist sentiments were extremely rare at that time, and where they existed they were not spoken. This is perhaps because a strong feeling of vulnerability still existed after the war. … We were born with the feeling that, as a nation, we were always in a kind of “circle defense.” It developed into a siege mentality.

Sagdeev, Roald Z. 1994. The Making of a Soviet Scientist: My Adventures in Nuclear Fusion and Space from Stalin to Star Wars. Wiley, New York, pp. 44-45.
Roald Sagdeev book