Why were there turning points in the Nuclear Arms Race?
I am not sure exactly what you mean by this question, but I am going to try to take a shot at it. Throughout the arms race America seemed to be lagging behind the USSR primarily because the USSR only broadcasted successful launches, while the US broadcasted all launches, successes and failures. You can see how that would make the moon landing appear like the US won against the odds. The arms race also wounded the USSR very deeply. Their economy was far from stable, they were exporting raw materials for far less money than democratic countries were exporting assembled goods, their technology was lacking, and they were putting on a facade of being economically equal to democratic nations while they were struggling to hold it together. The empire was about to begin to fall apart after the “thaw” or “destalinization” under Khrushchev that lead to attempted revolutions in Hungry and Poland that were answered by the Brezhnev doctrine (Khrushchev said that Stalin was too harsh, and lightened
