The backdrop for the story is the upcoming Preakness. Certain members of the Joint Chiefs of Staff are exchanging cable transmissions, ostensibly for purposes of placing bets on the race. What they are really up to is plotting a military coup.
Inspiration for the story was derived, in part, by the revelations in 1933 by USMC General Smedley Butler that certain wealthy businessmen had approached him to learn if he would be willing to lead the county after a completed coup.
The story features the outspoken head of the Joint Chiefs, Air Force General James Matsoon Scott (ably portrayed by Burt Lancaster) who espouses a conservative hard line and who is at odds with the progressive president. The character evokes shades of real-life retired General Edwin Walker who was making speeches at conservative rallies in 1961-62.
After reading an advance copy of the novel, President John F. Kennedy was so impressed with its warning against a conservative agenda dominating the military that he prevailed upon his Hollywood contacts to have the story made into a movie.
President Kennedy did not live to see the 1964 movie release. Lee Harvey Oswald used his newly purchased Carcano carbine to shoot at retired General Walker in April 1963. He is said to have fired the same rifle on November 22, 1963, to assassinate President Kennedy.