United States Air Force Brigadier General Jack D. Ripper, the commander of Burpelson Air Force Base, orders his executive officer, Group Captain Lionel Mandrake (an exchange officer from the Royal Air Force), to put the base on alert, confiscate all privately owned radios from base personnel and issue "Wing Attack Plan R" to the planes of the 843rd Bomb Wing. The planes, flying B-52 bombers armed with hydrogen bombs, are on airborne alert two hours from their targets inside the USSR. All the aircraft commence attack flights on the USSR and set their radios to allow communications only through their CRM 114 discriminators, which are designed to accept only communications preceded by a secret three-letter code known only to General Ripper. Happening upon a radio that had been missed earlier and hearing regular civilian broadcasting, Mandrake realizes that no attack order has been issued by the Pentagon and tries to stop Ripper, who locks them both in his office. Ripper tells Mandrake that he believes the Soviets have been fluoridating American water supplies to pollute the "precious bodily fluids" of Americans. Mandrake realizes Ripper has gone completely mad.
The film's trailerIn the War Room at the Pentagon, General Buck Turgidson briefs President Merkin Muffley and other officers about how "Plan R" enables a senior officer to launch a retaliatory nuclear attack on the Soviets if all of his superior officers have been killed in a first strike on the United States. Trying every CRM code combination to issue a recall order would require two days, so Muffley orders the U.S. Army to storm the base and arrest General Ripper. Turgidson, noting the slim odds of recalling the planes in time, then proposes that Muffley not only let the attack proceed but send reinforcements. Muffley rejects Turgidson's recommendation and instead brings Soviet ambassador Alexei de Sadeski into the War Room to telephone Soviet Premier Dimitri Kissov. Muffley warns the Premier of the impending attack and offers to reveal the targets, flight plans, and defensive systems of the bombers so that the Soviets can protect themselves.
After a heated discussion with the Premier, the ambassador informs President Muffley that the Soviet Union created a doomsday machine as a nuclear deterrent; it consists of many buried cobalt bombs, which are set to detonate automatically should any nuclear attack strike the country. The resulting nuclear fallout would render the Earth's surface uninhabitable for 93 years. The device cannot be deactivated, as it is programmed to explode if any such attempt is made. The President's German scientific advisor, the paraplegic former Nazi Dr. Strangelove, points out that such a doomsday machine would only be an effective deterrent if everyone knew about it; de Sadeski replies that the Soviet Premier had planned to reveal its existence to the world the following week at the Party Congress.
When the U.S. Army troops gain control of Burpelson General Ripper commits suicide. Mandrake deduces Ripper's CRM code from doodles on his desk blotter and relays it to the Pentagon. Using the code, Strategic Air Command successfully recalls all of the bombers except for one, commanded by Major T. J. "King" Kong. Because its radio equipment was damaged by a Soviet SAM, it is unable to receive or send communications. To conserve fuel, Kong flies below radar and switches targets. Because the Soviet attack also damaged the bomb bay doors, Kong enters the bay and repairs the electrical wiring. When he is successful, the bomb drops with him straddling it. Kong joyously hoots and waves his cowboy hat as he rides the falling bomb to his death.
In the War Room, Dr. Strangelove recommends that the President gather several hundred thousand people to live in deep underground mines where the radiation will not penetrate. Worried that the Soviets will do the same, Turgidson warns about a "mineshaft gap" while de Sadeski secretly photographs the War Room. Dr. Strangelove suddenly stands up out of his wheelchair. As Strangelove exclaims, "Mein Führer, I can walk!" the doomsday device explodes.
