Eric Braeden
Dr Charles Forbin
Acting
Susan Clark
Dr. Cleo Markham
Acting
Gordon Pinsent
The President
Acting
William Schallert
CIA Director Grauber
Acting
Georg Stanford Brown
Dr. John F. Fisher
Acting
Willard Sage
Dr. Blake
Acting
Alex Rodine
Dr. Kuprin
Acting
Martin E. Brooks
Dr. Jefferson J. Johnson
Acting
Marion Ross
Angela Fields
Acting
Dolph Sweet
Missile Commander
Acting
Byron Morrow
Secretary of State
Acting
Lew Brown
Peterson
Acting
Sid McCoy
Secretary of Defense
Acting
James Hong
Dr. Chin
Acting
Robert Cornthwaite
First Scientist
Acting
Tom Basham
Thomas L. Harrison
Acting
Leonid Rostoff
Russian Chairman
Acting
Serge Tschernisch
Translator
Acting
John Davey
Military officer on phone (uncredited)
Acting
Paul Frees
Colossus (voice) (uncredited)
Acting
Fred Holliday
Military Computer Entry - Missile Launch (uncredited)
Acting
Robert Quarry
Scientist (uncredited)
Acting
Don Ross
Logan US Air Force (uncredited)
Acting
William Traylor
Party Guest (uncredited)
Acting