Question: when was the last time the us detonated a nuclear weapon
Answer: United States Nuclear program start date 21 October 1939 First nuclear weapon test 16 July 1945 First fusion weapon test 1 November 1952 Last nuclear test 23 September 1992 Largest yield test 15 Mt / 63 PJ ( 1 March 1954 ) Total tests 1,054 detonations Peak stockpile 31,255 warheads ( 1967 ) Current stockpile ( usable and not ) 4,480 ( 2017 ) ( excludes retired and awaiting dismantlement ) 2,800 ( 2017 , retired ) Current strategic arsenal 1,411 deployed strategic nuclear warheads Maximum missile range 15,000 km ( 9,321 mi ) ( land ) 12,000 km ( 7,456 mi ) ( sub ) NPT party Yes ( 1968 , one of five recognized powers )