To what extent were economic realities the most important factor in pushing both sides towards detente by 1972?

The detente showed an improvement in relations between USA and USSR, as Brezhnev and Nixon were eager to form alliances. Although the economic realities were a big factor in pushing both countries towards a detente in 1972, there were other reasons for the alliance of both countries, for example the domestic considerations faced in either country, or relations with China. However the most important factor in pushing both countries towards a detente was the arms race and fear of war. Economic issues were very pressing to both sides, however a detente would have only been formed due to the requirement of peaceful co-existence after the Cuban Missile Crisis, which drove Nixon and Brezhnev to come to agreements.