One, Two, Three is a 1961 American comedy film directed by Billy Wilder and written by him and I.A.L. Diamond. It is based on the 1929 Hungarian one-act play Egy, kettö, három by Ferenc Molnár, with a "plot borrowed partly from" Ninotchka, a 1939 film co-written by Wilder. The comedy features James Cagney, Horst Buchholz, Pamela Tiffin, Arlene Francis, Leon Askin, Howard St. John, and others. It would be Cagney's last film appearance until Ragtime, 20 years later.The film is primarily set in West Berlin during the Cold War, but before the construction of the Berlin Wall, and politics is predominant in the premise.

C.R. "Mac" MacNamara is a high-ranking executive in the Coca-Cola Company, assigned to West Berlin after a business fiasco a few years earlier in the Middle East (about which he is still bitter). Nevertheless, Mac is angling to become head of Western European Coca-Cola Operations, based in London. After working on an arrangement to introduce Coke into the Soviet Union, Mac receives a call from his boss, W.P. Hazeltine in Atlanta. Scarlett Hazeltine, the boss's hot-blooded 17-year-old socialite daughter, is coming to Berlin and Mac receives the unenviable task of taking care of this young whirlwind.

An expected two-week stay develops into two months, and Mac discovers just why Scarlett is enamored of Berlin—she surprises him by announcing that she's married to a young man, Otto Piffl, who happens to be an East German Communist with ardent anti-capitalism views. The socialite couple are bound for Moscow to make a new life for themselves ("They've assigned us a magnificent apartment, just a short walk from the bathroom!"). Since Hazeltine and his wife are coming to Berlin to collect their daughter the very next day, this is obviously a disaster of monumental proportions, and Mac deals with it as any good capitalist would — by framing the young Communist firebrand and having him picked up by the Stasi, the East German secret police, who later force Otto to sign a confession that he's an American spy (after finally cracking from repeated exposure to the song "Itsy Bitsy Teenie Weenie Yellow Polka Dot Bikini" during interrogation).

Under pressure from his stern and disapproving wife (who wants to take her family back to live in the U.S.), and with the revelation that Scarlett is pregnant, Mac sets out to bring Otto back with the help of his new Russian business associates. With the boss on the way, he finds that his only chance is to turn Otto into a son-in-law in good standing — which means, among other things, making him a capitalist with an aristocratic pedigree (albeit contrived). In the end, the Hazeltines approve of their new son-in-law (upon which Mac learns from Hazeltine that Otto will be named the new head of Western European Operations—with Mac getting a promotion to VP of Procurement (back in Atlanta) Mac reconciles with his family at the airport, and to celebrate his promotion, offers to buy his family a Coke. Ironically, after handing out the Cokes to his family, he realizes upon inspection that the final bottle he takes for himself is actually Pepsi-Cola.