A post-war period or postwar period is the interval immediately following the ending of a war and enduring as long as war does not resume. A post-war period can become an interwar period or interbellum when a war between the same parties resumes at a later date (e.g., the period between World War I and World War II). By contrast, a post-war period marks the cessation of conflict entirely.
In Western usage, the post-war era or postwar era is the period of time since the end of World War II, even though many nations involved in the Second World War have been involved in multiple wars since.Year spans of the post-World War II era
Though technically, of course, even the present is "post-war" in the sense World War II is over, "post-war" is generally used to specify a shorter period after the war but which has now ceased.
In some British usage, "post-war" refers to the period from the election of Clement Attlee in 1945 to that of Margaret Thatcher in 1979, the period of the postwar political consensus, while it may also refer to an even shorter period; ending in 1960 or shortly after and corresponding to the greater 1950s era.
Considering the post war era equivalent to the Cold War, the post-war era is even sometimes considered to include the 1980s, putting the end at 1990 which was the year the last ice between the West and the Marxist world thawed. However the 1990s are almost never considered part of the postwar era.