Détente

Détente refers to the process of thawing of relations between the United States and Russia between the late 1960s and early 1970s by resuming arms talks following events that had brought states to the brink of nuclear war. (...) In practical terms, détente led to formal agreements on arms control and the security of Europe. A clear sign that a détente was emerging was found in the signing of the Nuclear Nonproliferation Treaty in 1968.

(...) The breakdown of détente in the late 1970s stalled progress on arms control. Ultimately, the United States and the Soviet Union had different visions of what détente meant and what its pursuit would entail.

Source: https://history.state.gov/milestones/1969-1976/detente