Aside from doing Marylin Monroe, a club as exclusive as eating at McDonalds, JFK and his counterpart Nikita Khruschev were responsible for stopping what was about to become a nuclear WW3. During the Cuban Missile Crisis (Missiles of October, 1962), the Russians were setting up nuclear ballistic launchers in Cuba, the US blockaded the island and when Russian ships tried to run the blockade, the situation came to a head. New, young JFK and the older experienced Khruschev had to fend off hawks on both sides to make the right decisions to prevent nuclear war. Behind the scenes, two other new statesman, Robert Kennedy and Anatoly Dobrynin also worked to come to a peaceable solution.
An incident that didn't come out until years later, the US Navy dropped signal depth charges, which are small, on a Soviet sub at the blockade. Unknown to the US, the sub had nuclear tipped torpedoes, and were under standing orders that if any hull breach, they could launch. It required 3 officers to agree to launch and one, Vasili Arkhipov, would not agree and convinced the Captain to surface so they could resume radio contact with Moscow. Arkhipov has been referred to in the US as the man who prevented nuclear war.
Bob