Dr Charles Forbin
Dr. Cleo Markham
The President
CIA Director Grauber
Dr. John F. Fisher
Dr. Blake
Dr. Kuprin
Dr. Jefferson J. Johnson
Angela Fields
Missile Commander
Secretary of State
Peterson
Secretary of Defense
Dr. Chin
First Scientist
Thomas L. Harrison
Russian Chairman
Translator
Military officer on phone (uncredited)
Colossus (voice) (uncredited)
Military Computer Entry - Missile Launch (uncredited)
Scientist (uncredited)
Logan US Air Force (uncredited)
Party Guest (uncredited)
