The 10 most shocking revelations from declassified US documents

It’s no mystery that the United States government has many secrets and, throughout the years, they have been forced to reveal some of them. Many are quite shocking, but of course, the biggest secret is the one we’ll never know.

Operation Northwoods was a proposed plan to stage false terrorist attacks across the United States and blame the Cuban government to justify invading the island in the early 1960s.

Ultimately, President Kennedy rejected the plan, which was only declassified in the late 1990s. However, it was hardly the only time Castro was in the CIA's crosshairs.

Documents declassified in 2007 revealed that the CIA had allied with Sam Giancana, head of the Chicago Outfit, in the early 1960s to try to assassinate Fidel Castro.

The plan was either poison Fidel Castro’s food, drinks, or cigars. However, after several unsuccessful attempts, the operation was canceled due to the Bay of Pigs Invasion.

During the Cold War, the CIA (along with NATO) also supported stay-behind groups in mainland Europe (most notably, Italy) in what has been known as Operation Gladio, under the excuse of preparation in case the Soviet Union invaded Western Europe.

Operation Gladio prepared armed caches, escape routes, and recruited far-right elements (including former Nazis and Italian Fascists), who engaged in terrorist attacks in the name of fighting Communism.

After World War 2, US President Harry S Truman authorized Operation Paperclip with the aim of recruiting scientists and engineers in Nazi Germany that could be useful for the United States, particularly its space program.

Hundreds of scientists were brought to the United States, including NASA legend Wernher von Braun. On paper, members of the Nazi Party were excluded. In reality, the OSS (the predecessor of the CIA) hid and destroyed evidence of their connections with the Third Reich.

The US involvement in Southeast Asia escalated after the Gulf of Tonkin Incident, when North Vietnamese troops attacked the USS Maddox on August 2 and August 4 of 1964. It shaped the Vietnam War as we remember it today.

Pictured: The USS Constellation in the Gulf of Tonkin in August 1964.

However, documents declassified in the 2000s reveal that the August 4 attack never happened. The US Navy claims that this mistake was due to miscommunication and not a deliberate attempt to force President Lyndon Johnson to retaliate without consulting Congress.

On the lighter side, the CIA tried to train cats in the 1960s to spy on Soviet government buildings. Under the codename Acoustic Kitty, US intelligence invested millions of dollars to essentially wire a pet.

Sadly, the program came to an abrupt end when the first and only known feline spy in history was run over by a car.

Another CIA experiment was Project MKUltra. From the 1950s to the 1970s, US intelligence used thousands of citizens as unwilling test subjects to try mind-altering techniques such as hallucinogenic substances, electroshock, and hypnosis that could be used for torture, interrogation, and mind control.

The last documents related to MKUltra were declassified in 2001. However, since most files were destroyed in 1973 by orders of CIA director Richard Helms, we will never know the true extent and horrors of the program.

Pictured: Richard Helms with Richard Nixon in 1969.

A more bizarre program was the Stargate Project, a US Army unit dedicated to investigating the potential military application of psychic phenomena.

The Stargate Project was terminated and declassified in 2005, after yielding no results. It's probably better remembered for inspiring the book 'The Men Who Stare at Goats', later made into a movie with George Clooney and Jeff Bridges.

In 1961, a Boeing B-52 carrying two nuclear bombs broke in midair, dropping its content near Goldsboro, North Carolina. One bomb went down in a parachute while the second fell into a field.

It was only in 2013 that it was revealed that one of the bombs, 250 more destructive than the one used in Hiroshima, came close to detonating. The explosion would have been large enough to kill everything within a circle of 8.5 miles (ca. 14 km).

Speaking about the space program, Richard Nixon wrote an alternative message in case the crew of the Apollo 11 Mission didn’t make it.

“Fate has ordained that the men who went to the moon to explore in peace will stay on the moon to rest in peace.” Nixon’s speech declared. “These brave men, Neil Armstrong and Edwin Aldrin, know that there is no hope for their recovery. But they also know that there is hope for mankind in their sacrifice.”