Best movies like G-men vs. the Black Dragon

The Unseen Enemy in this wartime meller is Nick (Leo Carrillo), the outwardly effusive manager of a San Francisco waterfront café. To make enough money to ensure his daughter Gen's (Irene Hervey) entree into society, Nick sells his services to a gang of foreign spies, who then use Nick's establishment as a rendezvous point. The plan is to covertly send out a Japanese vessel for the purpose of raiding and destroying American merchant ships. The spies' secret code is hidden in the lyrics of a song called "Lydia", which the unwitting Gen performs on request day after day.

A Nazi spy passes himself off as an optometrist in San Francisco's waterfront district. Someone robs him of his code book, and he must get it back.

An American military officer and his wife move to a cottage in what they think is the peaceful English countryside, only to discover the area is a hotbed of spies and secret agents.

Royce is a member of the ultra-secret service "Black Hole", working for the US Government on top-secret missions. When the senator responsible for forming Black Hole disbands the organization, Royce's fellow Black Hole members plot revenge on the man responsible for them losing their jobs. Royce decides not to join them, instead deciding to thwart their attempts to exact revenge on the senator.

An American ballistics expert in Turkey finds himself targeted by Nazi agents. Safe passage home by ship is arranged for him, but he soon discovers that his pursuers are also on board.

A nightclub star helps trap an enemy agent on the trail of an American newsman.

Blind detective Duncan Maclain gets mixed up with enemy agents and murder when he tries to help an old friend with a rebellious stepdaughter.

A greasy spoon diner provides a base for a spy smuggling nuclear secrets.

A bunch of waterfront youths pursue the Sea Raiders, a gang of saboteurs.

A superhero known as The Black Commando battles Nazi agents who use explosive gases and artificial lightning to sabotage the war effort.

Modesty Blaise, a secret agent whose hair color, hair style, and mod clothing change at a snap of her fingers is being used by the British government as a decoy in an effort to thwart a diamond heist. She is being set up by the feds but is wise to the plot and calls in sidekick Willie Garvin and a few other friends to outsmart them. Meanwhile, at his island hideaway, Gabriel, the diamond thief has his own plans for Blaise and Garvin.

Based on a successful comic book that began in 1941, the Blackhawks were seven flyers who banded together during WW II to fight the Nazis. After the war, they continued to fight evil where ever they find it. In this movie, they are battling a group of spies and saboteurs bent on destroying democracy. The Blackhawks foil a succession of plots, with a cliff hanger ending in each episode.

American, Chinese and Australian agents join forces to stop the Nazis from obtaining the formula for synthetic fuel.

A mad scientist attempts to rule the world by creating various elaborate inventions.

Dana Andrews plays Bill Roberts, an American radio commentator station in Berlin in the months before Pearl Harbor. Having witnessed Nazi brutalities first hand, Roberts hopes to alert his listeners of impending dangers, and does so by sending out coded messages during his broadcasts. The Gestapo begins to suspect something and assigns glamorous secret agent Karen Hauen (Virginia Gilmore) to spy on Roberts. When she discovers that her own father (Erwin Kaiser) is supplying Roberts with vital secrets, she turns her back on the Nazis and joins our hero in his efforts.

Nazi spies use a stolen shortwave transmitter prototype to broadcast top secret shipping info to an offshore Japanese sub. To nab the spy ring, the Government has the West Coast's top radio engineers fired and shadowed to see if the Nazis recruit them to complete work on the prototype radio. Radio engineer Lew Deerhold, a resident alien without a job to pay for his adorable little ward Gina's life-saving operation, falls prey to the spy ring, and is swept up in a maelstrom of deceit and danger.

Four flying G-Men protect America against enemy spies; one of the four assumes the identity of The Black Falcon, to befuddle the saboteurs even further.

A former US Operative, who lived in Russia in his earlier years and had been married there with a child, comes out of retirement to face down a former enemy, now running as a candidate for President in modern Russia. Working with a Russian policewoman, they work to uncover a plot to use biological weapons against certain factions of the Russian people to commit genocide. The virus would also be released in other populations, but would be treated making the candidate a hero. A side plot has the agent being reunited with his long lost daughter.

Several murders of nuclear scientists, that baffles Scotland Yard, occur in London about the same time that Bill Locklin, a special officer from the United States State Department, arrives to oversee the transfer of Professor Leon Dushenko, a Russian scientist who as fled the U.S.S.R. An attempt is made on Dushenko's life with a monkey's paw-print found at the scene.

Sebastian is an undisciplined mathematics genius who works in the "cipher bureau" of the British Intelligence. While cracking enemy codes, Sebastian finds time to romance co-worker Rebecca Howard.

A Communist spy ring in Japan is hard at work trying to sabotage the American war effort during the Korean War, using kidnapping, murder and a disturbed former kamikaze pilot. A U.S. secret agent, posing as a reporter, is dispatched to Tokyo to put a stop to these nefarious activities.

The war lords of a potential enemy of the US has the spy ring, led by John Baroda, the Spy King and his aide Nitra, sabotaging the plans for a vast defense system of radar stations along the American borders. Radar Defense Bureau operative Chris Calvert comes to the rescue of a brilliant radar scientist, Joan Hughes, who has been kidnapped by Baroda henchmen in chapter 1 ("The Fatal Fog"), and the two battle together before putting an end to the Spy King in the aptly-named chapter 12, "Day of Reckoning".

During WWI pretty German master spy Helene von Lorbeer is sent undercover to London to live with the family of a high-placed British official where she is to rendezvous with the butler Valdar, also a spy, and help him transmit secret war plans back to Germany.

A newlywed suspects her husband of being a Communist spy.

Enemy agents are everywhere and they are sabotaging all important war deliveries. The body of a hobo found in a train wreck had a money belt with $50,000 and a tattoo of a circle and arrow. This is a tattoo for saboteurs for hire and Brass must impersonate the dead man to find out what his orders are. As Steve Coe, he meets with the band of enemy agents in California and everything goes well until the wife of the dead 'Hobo' shows up. Luckily, Gabby is able to save Brass and Brass learns what is his assignment. He is to board the USN airship 'Mason', which is testing the super secret Inertia Projector, and destroy the airship.

A training film for OSS agents who are to be dropped behind enemy lines.

An American nightclub singer in 1940's Singapore becomes a spy for America in an effort to get back at the invading Japanese army. Based on a true story.

A French air ace discovers that his showgirl wife's first husband is still alive.

Government agents try to thwart smugglers, while some sort of plot unfolds, about a hidden treasure revealed by cursed coins.

American federal agent Clark Stuart is on assignment in Santa Fe to draw up a trade agreement with the newly installed Mexican governor. Meanwhile, Walter Jamison leads a wagon train from Missouri, hoping to take advantage of the new agreement. Among Jamison's passenger are famed frontiersman Jim Bowie and a very youthful Kit Carson. The destinies of all these personalities intersect when villainous ex-governor DuPrey schemes to undermine the treaty and take over the New Mexico territory for his own vile purposes. Somewhere along the way, Davy Crockett joins the "good guys" in their efforts to thwart the despicable DuPrey.

In the office of Major Northfield, the quartermaster of the Pacific Coast, a leak has been discovered which may endanger the safety of American transports that are secretly carrying troops across the Pacific. Nara-Nara, a Japanese detective, is assigned to the case because his country has guaranteed safety to these transport ships. Nara-Nara believes that Northfield is guilty, although in reality it is Northfield's secretary Kitty Little, a girl of German ancestry, who is passing information to Dr. Ebell Smith, a German agent. Nara-Nara falls in love with Kitty, but soon after discovers that she is the leak in the quartermaster's office.

Tom Cameron learns that his twin brother is with a group of German spies. They intend to thwart the government's efforts to round up horses for military service.

Carlos Delargo, the banished son of a royal princess of Mandorra, is returned to the kingdom to be tried for a murder change. However, he is freed by King Lorenzo, whom bears a remarkable resemblance to Delargo. When the king is wounded by assassins sent by Napoleon, Delargo takes over the throne at the request of the Prime Minister in a plot to thwart the traitors. He also falls in love with Princess Teresa, the king's fiancée.

Parisot, a French spy in World War 1, returns home on a secret mission to visit his mother, and finds that Victoria, the wife of a German general, is billeted in the Parisot home while waiting to see her husband. Victoria discovers that Paul is a spy and, although fascinated by him, plans to reveal his identity to her husband. When the latter is unable to visit her, she attempts to go to the German army headquarters.

Alice Grayson's uncle develops a wireless torpedo that can be controlled by radio. After he announces his invention to several of his colleagues, two of them murder the scientist, steal the blueprints and prototype, and make plans to sell both to the highest bidder. When Alice discovers the identity of the thieves, the intrepid heroine, with the help of Bob Moore, her two-fisted boyfriend, desperately tries to recover the plans and torpedo before enemy countries can unleash the torpedoes against American ships. (IMDb)

Near the end of the war in Germany, GI Steve Boland, a self-described "sharp-operator", meets a German girl, Ilsa, and they fall in love. Ilsa's brother Karl, whom she has not seen in three years, and his fellow Nazi Ludwig visit Ilsa. Karl proudly informs her that he and Ludwig are "Werewolves", a group of Nazi assassins parachuted behind Allied lines for the purpose of killing Allied High Command officers. She and Steve go to Army Intelligence with their information, where Steve is immediately arrested for being A.W.O.L. Captain Melton of Army G-2 intervenes on Steve's behalf, as G-2 has had a suspicion about the existence of the "Werewolves" but no concrete info before now.

A movie serial in 12 Chapters: US naval officer Don Winslow is given command of Tangita Island, near Pearl Harbor, where a ring of saboteurs is trying to destroy ships carrying supplies to the troops stationed in the islands and sabotage the war effort under orders from an unknown leader.

Captain Bob Dayton and Lieutenant Ed Carey are partners in a company called "Sky Raiders" which seeks US government contracts for its inventions. Enemy spies attempt to steal, sabotage and discredit the inventions and founders of the company.

A Nazi spy ring is after a chemical formula that increases the power of ordinary gasoline for U.S. Army aviation use. Two U.S. chemical companies are developing the formula, with each working on half for security purposes. The spies get half the formula and know that either of two chemists, Robert Norton or Tom Fielding, knows the rest. They capture Fielding, through a ruse by gang member Linda Pavlo, and threaten the life of his sister Nancy and his mother if he does not give them the formula. To protect his friend Fielding, who does know the formula and is engaged to Nancy, Tom pretends to know the secret and boards the Dawn Express plane with the spy leader and his gang.

Adventures of an American Secret Service-girl in search of an important German secret during the war.

Spies from Japan conspire to steal the Channing "preparedness" fortune and invade the United States, beginning in New York, then allying themselves with Mexicans across the border. They are stopped by the efforts of munitions factory heiress Patria Channing and U.S. Secret Service agent Donald Parr.

Four youthful cadets are implicated in a series of murders, and must attempt to clear themselves of suspicion.

When Willie leaves home to join the war effort he is all ready to become a hero, but he is only frustrated when his posting ends up to be in his home town, and he is recruited into training, keeping him from the action. However, when he finds himself accidently behind enemy lines he unexpectedly becomes a hero after all.

The Lone Wolf goes undercover in Egypt to foil a Nazi plot to bomb and disable the Suez canal, which is vital to England's war effort.

Three soldiers in Korea go through inner torment when they're ordered to execute an enemy soldier.

During World War II, Chinese guerrillas fight against the occupying Japanese forces. A young woman is the secret leader of the villagers, who plot to rescue two downed Flying Tigers pilots who are currently in the custody of the Japanese. The rescue mission takes on even more importance with the arrival of a Japanese general, which signals a major offensive taking place in the area.

The Phantom Rider helps Mary Grayson thwart a plot to steal her land.

A young Japanese-American orphan in California is taken in by a priest who is actually a Japanese secret agent and a samurai warrior. Due to the samurai's training, the boy murders his English teacher, kills the American parents who have adopted him, smuggles Japanese secret plans into the country, and eventually becomes the governor of California with plans to infiltrate Japanese spies into the state so they can take over.

Phillip Gresson is in the employ of the British secret service, while heroine Judith is a spy for the Enemy. Hoping to gain possession of the usual Secret Plans, Judith pretends to be in love with Phillip. Only after nursing the seriously wounded Phillip back to health does Judith come to the realization that she genuinely loves him.

Secret Service officer Richard Paget receives a letter from his twin brother John imploring him to take over his identity after he commits suicide, so that Richard can subvert the plans made by the airplane company which John had financed, to make defective planes for the United States to use in the war.