William Shatner
Narrator
Acting
Edward Teller
Self - Nuclear Physicist
Acting
W.H.P. Blandy
Self - Commander Joint Task Force One (archive footage)
Acting
Frank H. Shelton
Self - Nuclear Weaponeer
Acting
Dwight D. Eisenhower
Self - U.S. President (archive footage)
Acting
Adlai Stevenson
Self - U.S Ambassador (1961-1965) to the UN (archive footage)
Acting
Randall William Cook
Newsreel Narrator (archive sound)
Visual Effects
Nikolai Bulganin
Self (archive footage)
Acting
Winston Churchill
Self (archive footage)
Acting
Everett Dirksen
Self (archive footage)
Acting
Albert Einstein
Self (archive footage)
Acting
Enrico Fermi
Self (archive footage)
Acting
Reed Hadley
Self (archive footage)
Acting
Averell Harriman
Self (archive footage)
Acting
Adolf Hitler
Self (archive footage)
Acting
Hubert H. Humphrey
Self (archive footage)
Acting
John F. Kennedy
Self (archive footage)
Acting
Nikita Khrushchev
Self (archive footage)
Acting
Anastas Mikoyan
Self (archive footage)
Acting
Marilyn Monroe
Self (archive footage)
Acting
J. Robert Oppenheimer
Self (archive footage)
Acting
Franklin D. Roosevelt
Self (archive footage)
Acting
Dean Rusk
Self (archive footage)
Acting
Woodrow P. Swancutt
Self (archive footage)
Acting
Leó Szilárd
Self (archive footage)
Acting
Mark Tapscott
Announcer (archive footage)
Acting
Paul Tibbets
Self (archive footage)
Acting
Wernher von Braun
Self (archive footage)
Acting
John von Neumann
Self (archive footage)
Acting
Mao Zedong
Self (archive footage)
Acting
Roy Neal
Self (uncredited)
Acting