Throughout the 1960s and 1970s, the USA and the Soviet Union (USSR) tried to reduce the tension that existed between them.
This became known as the 'détente era'. Although there continued to be mistrust and suspicion, this period saw cooperation and agreement on both sides.
There are a number of reasons why the superpowers altered the way they related to each other:
The Cuban Missile Crisis 1962 emphasised to both sides the risk of not cooperating with each other. It was clear to the world how easily nuclear war could develop, even over conflicts in small countries.
The USA was committed to the Vietnam War and could not afford to assign troops or money to other areas. Détente could perhaps help the Americans find a way out of Vietnam.
The USSR and China had major political disagreements even though both sides were communist. The USSR saw China as a threat and wanted to be friendlier with the USA.
Détente was a propaganda opportunity for both sides. They each could portray themselves as peacemakers who were concerned with the safety of the world.
Détente helped the superpowers save money as they were able to reduce the amount spent on the arms race and focus on problems in their own countries. The USA had suffered from inflation and as a result of the unpopularity of the Vietnam War and his falling support, President Lyndon Johnson had not been able to pass reforms to help the poor. The people of the USSR were suffering from food shortages and poor housing.