With all of the history of war, and the human race's history unfortunately has been a good deal more war than peace, with nuclear weapons distributed all through the world, and available, and the strong reluctance of any people to accept defeat, I see the possibility in the 1970's of the President of the United States having to face a world in which 15 or 20 or 25 nations may have these weapons.
The President's News Conference of March 21, 1963
John F. Kennedy Quotations[jfklibrary.org]