détente

dāˈtänt also detente n.the easing of hostility or strained relations, especially between countries: a serious effort at détente with the eastern bloc.

See the Introduction, Abbreviations and Pronunciation for further details.

Literally ‘loosening’. Détente was used to refer to periods of reduced tension in relations between the United States and the Soviet Union during the Cold War. It was closely associated with the process (and progress) of arms control, and the main period of détente ran from the Partial Test Ban Treaty 1963 to the late 1970s. The term has fallen out of use with the end of the Cold War, but it has generic standing and can be used to describe any easing of tension in relations between states that are otherwise expected to be hostile.

— Barry Buzan