Several brigadier generals (American, British, and French) are unexpectedly taken prisoner by the Italians while arguing military tactics in a sauna - which is a public relations disaster. They are held in an Italian villa run as a top level prison camp by benevolent Italian Colonel Ferrucci. Being all of the same rank, none is in command and they are forced to plan escapes by committee, with predictably ineffective results.
The Great Wooley (Jerry Lewis) is a magician who is entertaining GIs in Japan. Upon their arrival, he causes a series of unfortunate mishaps for the headliner, actress Lola Livingston (Marie McDonald), including tearing her dress, knocking her down a flight of stairs, and rolling her up in the red carpet. An orphan, Mitsuo Watanabe (Robert Hirano) witnesses the spectacle and laughs for the first time since his parents died. When his aunt Kimi Sikita (Nobu McCarthy) brings the boy to Wooley to thank him, he and the boy become close, which irritates the aunt's boyfriend, a Japanese baseball player, as well as a USO liaison (Suzanne Pleshette) who has fallen for Wooley.
In the aftermath of a big battle during World War II, Brigadier General Charles Lane (Kent Smith), Master Sergeant Murphy "Murph" Savage (Glenn Ford) and Corporal Chan Derby (Red Buttons) find themselves cut off. The general takes over a farmhouse belonging to annoyed Frenchwoman Simone (Taina Elg). Lane determines that there is a gap in the lines and decides to organize a defense from whatever stragglers he can gather together. Shortly afterwards however, he is killed saving Murph's life.
Second Lieutenant Peter Stirling (Donald O'Connor) is caught behind Japanese lines in Burma during World War II. Francis, a talking Army mule (voiced by Chill Wills), carries him to safety. When Stirling insists that the animal rescued him, he is placed in a psychiatric ward. Each time Stirling is released, he accomplishes something noteworthy (at the instigation of Francis), and each time he is sent back to the psych ward when he insists on crediting the talking mule. Finally, Stirling is able to convince General Stevens (John McIntire) that he is not crazy, and he and the general become the only ones aware of Francis' secret. In an effort to get himself released from the psych ward, Stirling asks Stevens to order Francis to speak, but the mule will not obey until it becomes clear that Stirling will be arrested for treason if he remains silent.
Flagg (Victor McLaglen) and Quirt (Edmund Lowe) find themselves transferred from Russia to Brooklyn to South America, in each place squaring off over a local beauty.
A wartime outfit of U.S. soldiers is assigned to capture a village in Sicily, but upon arrival, they discover that the town has been expecting them and will willingly turn itself over to the Americans' rule, provided they are permitted to complete a soccer match and a wine festival.
After her client Albert Osborne (Robert Benchley) makes a pass at her, Susan Applegate (Ginger Rogers) quits her job as a scalp massager for the Revigorous System and decides to leave New York City and return home to Stevenson, Iowa. Upon arriving at the train station, she discovers she has only enough money to cover a child's fare, so she disguises herself as a twelve-year-old girl named Su-Su. When a suspicious conductor catches her smoking, Su-Su takes refuge in the compartment of Major Philip Kirby (Ray Milland) who, believing she is a frightened child, agrees to let her stay with him until they reach his stop.
Wally Hogan (Hope) has things going his way. He is the manager-trainer of Bullet Bradley (Stanley Clements), a fighter who has just won the lightweight championship. Life suddenly takes a not-so-happy turn, however, when Bullet gets drafted. Hogan's gangster partners persuade him to enlist and keep an eye on the fighter, who is subsequently declared psychologically unfit for the Army. Enter Herbert Tuttle (Mickey Rooney), a draftee eager to have Hogan turn him into a fighter. Hogan reluctantly agrees only after he discovers Tuttle's aunt is the beautiful singer (Marilyn Maxwell) at a nightclub. From then on it's a case of stringing Tuttle along while trying to get close to his aunt. To further complicate Hogan's life there is a rulebook Military Police Officer who tries to squash the shenanigans.
After serving in Europe during World War II, Herbie Brown (Lou Costello) and Slicker Smith (Bud Abbott) return to the United States aboard a troop ship. Also onboard is their old nemesis, Sgt. Collins (Nat Pendleton). As the ship nears New York, Collins and his superiors search the men's belongings for contraband. A six-year-old French orphan, Evey (Beverly Simmons), whom Herbie and Slicker befriended, is found in Herbie's duffle bag. She is handed over to Lt. Sylvia Hunter (Joan Fulton), who delivers her to immigration officials in New York. However, during a shift change at the office, Evey is mistaken for a neighborhood kid and set free. Meanwhile, Herbie and Slicker are back to their pre-war occupation of peddling ties in Times Square. Collins is also back at his old job--a police officer assigned to the same beat. He is about to arrest the boys when Evey shows up and helps them escape.
Specialist Ray Elwood (Joaquin Phoenix) is a U.S. Army soldier stationed in Stuttgart, Germany, in 1989. Bored with the lack of a war, he instead devotes his attention to black market deals, as well as cooking heroin for a gang of drug-dealing Military Police led by Sergeant Saad. As a supply specialist, Elwood poses as a model soldier and friendly confidant to his incompetent commanding officer, Colonel Berman (Ed Harris), who gives Elwood the opportunity to turn Army protocol to his advantage. Berman has no idea what supplies his subordinate is requisitioning or that Elwood is sleeping with his wife (Elizabeth McGovern).
TV writer Greg Whitcomb did his military service heroically but now has settled into everyday life with a young wife, Katy. A letter from the war department arrives that Katy believes is calling Greg back to active duty from the Air Force reserve, but she hides it during a party celebrating their wedding anniversary.
Flagg and Quirt are veteran United States Marines sergeants whose rivalry dates back a number of years. Flagg is commissioned a Captain, he is in command of a company on the front lines of France during World War I. Sergeant Quirt is assigned to Flagg's unit as the senior non-commissioned officer. Flagg and Quirt quickly resume their rivalry, which this time takes its form over the affections of Charmaine, the daughter of the local innkeeper. However, Charmaine's desire for a husband and the reality of war give the two men a common cause.
Titled after a lyric in the Marines' Hymn, which contains the phrase "... to the shores of Tripoli" (which is, itself, a reference to the Battle of Derne) the film is one of the last of the pre-Pearl Harbor service films. When the film was in post-production the Pearl Harbor attack occurred having the studio shoot a new ending where Payne re-enlists.
Popular crooner Russ Raymond (Dick Powell) abandons his career at its peak and joins the Navy using his real name, Tommy Halstead. However, Dorothy Roberts (Claire Dodd), a reporter, discovers his identity and follows him in the hopes of photographing him and revealing his identity to the world.