The U.S. government's 1958 "what-if" film about nuclear war

... is entitled "The Power of Decision," and was recently declassified. It

may be the first (and perhaps the only) U.S. government film depicting the Cold War nightmare of a U.S.-Soviet nuclear conflict.  The U.S. Air Force produced it during 1956-1957 at the request of the Strategic Air Command.  Unseen for years and made public for the first time by the National Security Archive, the film depicts the U.S. Air Force's implementation of war plan "Quick Strike" in response to a Soviet surprise attack against the United States and European and East Asian allies. 

Check it out:



(Source.)