The correct answer is: "Detente".
The term 'detente' refers to a period in which the relatiohship between two countries have become more relaxed after a period of tensions.
It is used to refer to a period during the Cold War of improved relations between the US, which headed the Western bloc of capitalist countries and the URSS, that leaded the Eastern bloc of communist countries. It was promoted by Nixon, Kissinger and Brezhnev, and it lasted between 1969 and 1974. It ended when the URSS invaded Afganistan.