In the early 1970s we conducted three exercises in which we considered the consequences of a strategic nuclear exchange assuming a U.S. first strike. In 1972, the GS conducted the final exercise in the series and Brezhnev, Kosygin, Grechko, and several members of the government took part. <...> During the exercise three launches of ICBMs with dummy warheads were scheduled. Brezbnev was actually provided a button in the exercise and was to "push the button" at the appropriate time. Marshal Grechko was standing next to him and I next to Marshal Grechko. When the time came to push the button, Brezhnev was visibly shaken and pale and his hand trembled and he asked Grechko several times for assurances that the action would not have any real-world consequences. "Andrei Antonovich, are you sure this is just an exercise?"
Кстати, оттуда же - примечательный пассаж про недавно покинувшего нас великого борца за дело прогресса, который, по мнению нынешнего премьер-министра Канады, was a larger than life leader who served his people for almost half a century:
One example of our appreciation of the consequences of nuclear use: In the early 1980s Fidel Castro pressed hard for a tougher Soviet line against the U.S. up to and including possible nuclear strikes. The GS had to actively disabuse him of this view by spelling out the ecological consequences for Cuba of a Soviet strike against the U.S. This changed Castro's positions considerably.