What Were the Main Reasons why the USSR and US Moved to Detente between 1963-1975?

Detente, the beginning of the end of the Cold War between the Soviet Union and the United Sates began in 1963 and brought the long decades of tension to a close in 1975. The motives behind the paradigm shift towards cooperation were not those that reconciled the differences between the Eastern and the Western giants, but rather those that were built upon the limited, but common desire--- peaceful coexistence. The two countries, along with other states involved throughout the span of the Cold War years, had to change to adapt to a nuclear powered world and focus their attention on domestic concerns. The Cuban Missile Crisis, domestic concerns of both countries and the entry of China, as a powerful player in international politics, were among the main reasons why the US and the USSR moved to Détente between the twelve years in question.
The Cuban Missile Crisis of October 18-29, 1962, was a pivotal incident that demonstrated to the two countries, and the whole world, on the absolute necessity of creating a channel of peaceful communication between Moscow and Washington. …