A joker is appointed president of a small country and goes to war with his neighbor in this anarchical Marx brothers farce.
The government of Freedonia asks Mrs. Teasdale (Margaret Dumont) for another $20 million so they can reduce taxes; but she insists that Rufus T. Firefly be appointed president. Sylvania's ambassador Trentino (Louis Calhern) tells Vera Marcal (Raquel Torres) he can gain control of Freedonia by marrying Mrs. Teasdale, but he needs her to distract Firefly. Mrs. Teasdale hopes that Firefly (Groucho Marx) will follow in her late husband's footsteps. Firefly asks for money from Trentino. On his gala day Firefly says he likes a gal a day. Trentino hired spies Chicolini (Chico Marx) and Pinky (Harpo Marx), but he is disappointed since they are more interested in baseball. At a cabinet meeting Firefly quickly dispenses with old and new business. Workers want shorter hours; so he shortens the lunch hour. The war secretary resigns. Firefly makes the peanut peddler Chicolini his secretary of war. He recommends a standing army so they can save money on chairs. Firefly invites himself to Mrs. Teasdale's tea party, where he offers her a Rufus over her head. Firefly slaps Trentino, but they forget their differences until Trentino reminds him he called him an upstart. Firefly again slaps Trentino, who threatens war. Vera asks Firefly what she can do, and he says he'll tell her later.
Trentino tells Vera to get Firefly's war plans, and Chicolini and Pinky come to find them. Chicolini locks Firefly in and disguises himself as Firefly, as does Pinky. Pinky gets the combination to the safe from Mrs. Teasdale and runs into a mirror, breaking it. Then he and Firefly imitate each other where the mirror was. Chicolini comes in as the third Firefly and is arrested. At his trial when he is questioned, Chicolini puns around. A messenger says Sylvania is invading. Mrs. Teasdale tells Firefly she has intervened. Firefly offers his hand in friendship; but after considering what will happen if it is rejected, he slaps Trentino again. Suddenly everyone is singing about going to war. Firefly sends Pinky on a horse to announce war; but he is led astray by a blonde undressing and is joined in her bathtub by her husband. Firefly sends a telegram during the war. His secretary Bob Rolland (Zeppo Marx) says he is shooting his own men, while his war secretary Chicolini says he has changed sides. Firefly asks for help, and Pinky puts up a HELP WANTED sign. With four men and one woman, Firefly calls for three more women. They send out Pinky to sacrifice himself, and Firefly tells him they'll be thinking what a sucker he is. Finally Trentino is caught with his head in the door, is pelted with fruit, and surrenders.
This madcap farce satirizes how easily a nation can slide into a disastrous war. The games of spying and diplomacy are seen to be ridiculous, resulting in a buffoonery of the films about the world war.