systems of the modern era but the sole intercontinental nuclear weapon delivery system capable of reaching the US from the Soviet Union and vice versa. Before advances in precision guided munitions and physics package miniaturization, "city busting" or countervalue targeting, was a more likely nuclear war scenario, as effective counterforce warfare with nuclear weapons had yet to become all that conceivable, with the potential exceptions of being used in roles where a low degree of accuracy would not result in a waste of a bomb, such as destroying large "rear area" military bases, aircraft carriers, Communist human wave attacks, massive mine fields in trench warfare (which was what the Korean War escalated into), radiological area denial and used at night prior to a frontal assault in the hopes of inducing widespread enemy troop flash blindness. Practically all other counterforce uses of this eras nuclear weapons would be ineffective due to force dispersal, weather factors, poor munition accuracy and the unwieldy physics packages of the nuclear weapons of the era, making them generally unfit for the mobile battlefield. This would therefore make it likely that combatants who have escalated to the point of contemplating nuclear exchanges would use their nuclear weapons on immobile and valuable targets, such as the war supporting infrastructure of cities. It is now estimated that it was not until after 1957 that the USSR attained more than about 50 nuclear munitions in its nuclear weapons arsenal. Almost all of this stockpile was likely designed to be air dropped by the Myasishchev M-4 and Tupolev Tu-4 bombers as strategic nuclear weapons on US and West European NATO cities respectively. Large numbers of small true tactical nuclear weapons only began to seriously populate the USSR's stockpile in the 1970s and beyond. Legacy Appearance in other media The 1982 film The Atomic Cafe, a satirical collage documentary film, uses footage from the Duck and Cover. Both films (the documentary in 2016) were inducted into the National Film Registry. The video for "Weird Al" Yankovic's 1986 song "Christmas at Ground Zero" features footage from the film, mostly during an instrumental break. Bert the Turtle is shown in time with the lyric 'I'll duck and cover/ with my Yuletide lover'. The video for Peter Gabriel's 1980 song "Games Without Frontiers" features footage from the film at the end of song. The 2015 Oscar-winning film Bridge of Spies, about an exchange of captured