| William Devane | President John F. Kennedy |
| Ralph Bellamy | U.N. Ambassador Adlai Stevenson |
| Howard Da Silva | Soviet Premier Nikita Khrushchev |
| James Hong | U.N. Secretary-General U Thant |
| Martin Sheen | Att. Gen. Robert F. Kennedy |
| Keene Curtis | John McCone, Director CIA |
| Charles Cyphers | Press Photographer |
| Thayer David | Narrator |
| Clifford Davis | Theodore Sorensen, Special Counsel |
| Francis De Sales | Senator |
| John Dehner | Former Secretary of State Dean Acheson |
| Peter Donat | David Ormsby-Gore, British Ambassador to U.S. |
| Andrew Duggan | Gen. Maxwell Taylor, Army Chief of Staff |
| Richard Eastham | Gen. Shoup, USMC Commandant |
| Dana Elcar | Secretary of Defense Robert McNamara |
| Gene Elman | Russian Presidium Member |
| Ron Feinberg | Gen. Charles De Gaulle |
| Michael Fox | Soviet Marshal |
| Arthur Franz | Congressman Halleck |
| Larry Gates | Secretary of State Dean Rusk |
| Jerome Guardino | Reporter |
| Ted Hartley | American General |
| Bern Hoffman | Russian Presidium Member |
| Richard Karlan | Chief of the Presidium |
| Stacy Keach Sr | .W.E. Knox, President Westinghouse International |
| Wright King | Sen. Richard Russell |
| Will Kuluva | Valerian Zorin |
| Paul Lambert | John Scali, ABC Correspondent |
| Michael Lerner | Pierre Salinger, Whitehouse Press Secretary |
| Robert P. Lieb | Gen. Curtis LeMay, Air Force Chief of Staff |
| John McMurtry | Yefgani Yevtushenko |
| Byron Morrow | Sen. William Fullbright |
| Stewart Moss | Kenneth O'Donnell, Special Assistant to the President |
| Stuart Nisbet | Reporter |
| Buddy Ochoa | Television Assistant |
| James Olson | McGeorge Bundy, Special Assistant for National Security Affairs |
| Dennis Patrick | Llewellyn Thompson, Former U.S. Ambassador to the Soviet Union |
| Albert Paulsen | Ambassador Anatoly Dobrynin |
| Nehemiah Persoff | Foreign Minister Andrei Gromyko |
| William Prince | Secretary of the Treasury, C. Douglas Dillon |
| John Randolph | Secretary of State George Ball |
| Toby Russ | Waiter |
| Kenneth Tobey | Adm. George W. Anderson Jr., Chief of Naval Operations |
| Serge Tschernisch | Soviet Stenographer |
| Jay Vallera | Cuban Delegate |
| George Wyner | Civillian Aide |
| Harris Yulin | KGB Agent Alexander Fomin |
| James T. Callahan | David Powers, Special Assistant to the President |
| Peter Canon | Admiral's Aide |
| Doreen Lang | Mrs. Evelyn Lincoln, President Kennedy's Secretary |
