The world's most remarkable declassified intelligence operations

1. The British spy who danced to Russian “Kalinka”

On October 22, 2026, the UK National Archives released previously classified MI5 records revealing details of British spy Frank Clifton Bossard’s activities.

Bossard worked for Britain’s Ministry of Aviation. Between 1961 and 1965, he sold classified missile information to Soviet intelligence. He photographed secret documents in London hotel rooms. His Soviet handlers sent instructions through coded musical radio broadcasts.

Each melody carried a specific message:

• Moscow Nights: All well.
• Swan Lake: Use reserve D.L.E.
• Kalinka: Meet following Saturday at sunset at permanent meeting place.
• Sabre Dance: Cancel next drop.
• Volga Boat Song: Stop till further notice.

MI5 tracked Bossard’s movements and secretly recorded conversations inside his home.

On March 15, 1965, intelligence officers arrested him after he left a London hotel room. They found classified documents, photographic equipment and exposed film in his possession.

A court sentenced Bossard to 21 years in prison.

2. Operation Mincemeat: How a dead man fooled the Nazis

In April 1943, British intelligence placed a dead body in the sea near Spain. The man wore a military uniform and carried supposedly secret Allied documents. However, the officer named Major William Martin had never existed.

British intelligence officers Ewen Montagu and Charles Cholmondeley created his fictional identity. The documents suggested Allied forces were preparing to attack Greece and Sardinia. Their real target was Sicily.

German intelligence obtained the documents and believed they were genuine. German commanders consequently moved additional forces toward the false targets.

When Allied troops landed in Sicily in July 1943, the deception helped preserve their advantage.

An Imperial War Museums archival guide presents materials from the operation, including original intelligence documents and a fake identity card.

3. Agent GARBO and his imaginary spies

Spanish double agent Juan Pujol García convinced Nazi Germany that he controlled an entire network of informants in Britain. In reality, none of his agents existed.

Working for British intelligence under the codename GARBO, Pujol invented 27 fictional sub-agents. He supplied German intelligence with carefully prepared misinformation.

His most important deception came during the Allied landings in Normandy on June 6, 1944. GARBO convinced German commanders that the Normandy landings were merely a diversion. He claimed the main invasion would come later near Pas-de-Calais. As a result, Germany kept substantial forces there instead of sending them to Normandy. The deception helped Allied troops establish their foothold in France.

In September 2016, MI5 declassified additional records revealing details of GARBO’s work and personal life.

4. Operation Gold: A success or a failure?

During the Cold War, the CIA and Britain’s MI6 secretly built a tunnel beneath Berlin. Their target was Soviet military communications. The tunnel stretched approximately 450 meters from West Berlin toward telephone cables in East Berlin.

According to CIA records, the operation produced 443,000 fully transcribed conversations and 1,750 intelligence reports.

However, the Soviet Union knew about the tunnel before it even became operational. British intelligence officer George Blake, who secretly worked for the KGB, had exposed the plans. Despite this, Moscow allowed the operation to continue.

In April 1956, Soviet and East German personnel discovered the tunnel. Later assessments indicated that Soviet authorities had apparently not fed false information through the intercepted lines.

5. How the CIA tried to steal a Soviet submarine

In 1968, Soviet submarine K-129 disappeared in the Pacific Ocean. It carried three nuclear-armed ballistic missiles.

American intelligence located the wreck approximately five kilometers below the ocean’s surface. The CIA decided to recover the submarine and examine Soviet military technology.

But how could it retrieve a warship from the seabed without raising suspicion? The agency built a specially equipped vessel called the Hughes Glomar Explorer.

Billionaire Howard Hughes helped provide the cover story. Officially, the ship was supposedly designed to mine minerals from the ocean floor.

In 1974, the vessel lowered a massive mechanical claw to lift the submarine.

The operation achieved only partial success. During the recovery, the submarine’s hull broke apart. Some sections fell back to the seabed, while others reached the surface. The recovered section contained the remains of six Soviet submariners.

In 1975, details of the operation became public. Washington was forced to abandon further recovery attempts.

The CIA later published a detailed account of Project AZORIAN.

6. Operation ARGO: The movie that never existed

On November 4, 1979, militants seized the U.S. Embassy in Tehran and took its staff hostage. Six American diplomatic employees escaped capture and found shelter with Canadian diplomats.

The CIA devised an unusual rescue plan. Instead of presenting the Americans as diplomats, the agency decided to disguise them as a Canadian film crew.

CIA officer Tony Mendez helped establish a fake Hollywood company called Studio Six Productions. The team created advertisements, artwork and a screenplay for a fictional science-fiction movie titled Argo.

The six Americans received Canadian passports and new identities connected to the film production. On January 28, 1980, they successfully passed through Tehran airport and left Iran. All six escaped safely.

Canada’s role became public almost immediately. However, the CIA’s involvement remained classified until 1997. The agency later revealed details of the operation, including materials created for the fictional film.

7. Project CORONA: Satellites that dropped secret photographs from space

In the 1960s, long before digital satellite cameras existed, the CIA and U.S. Air Force used film-equipped satellites to photograph Soviet territory. After taking pictures, the satellites released capsules containing exposed film toward Earth. Aircraft then intercepted the descending capsules in midair over the Pacific Ocean.

The classified program was named CORONA. Its early missions repeatedly failed. On August 18, 1960, CORONA finally returned photographs suitable for intelligence analysis.

According to the CIA’s declassified history, that single mission photographed more Soviet territory than all previous U-2 reconnaissance flights combined.

The images helped American analysts assess Soviet missile systems, aircraft and military installations. In February 1995, the U.S. government authorized the public release of historical imagery from the CORONA program.

8. Spy pigeons

Not every intelligence experiment required sophisticated aircraft or secret agents. The CIA also experimented with pigeons carrying miniature cameras.

Engineers developed cameras light enough to attach to the birds’ chests. The idea was for a pigeon to fly over a target while returning home. Its camera would automatically photograph the area. The intelligence agency hoped pigeons could capture more detailed images than aircraft or satellites.

However, the birds did not always fly over their intended targets. According to the CIA Museum, the cameras ultimately proved ineffective.

Parts of the pigeon surveillance program remain classified. As a result, the experiment’s full history remains unknown.

Earlier, Qazinform News Agency reported that Switzerland’s Federal Intelligence Service released more than 200 pages of archival records on Nazi doctor Josef Mengele, known as the “Angel of Death.”