10 Dirty Government Secrets Revealed by Declassified Files

Governments classify documents for many reasons. Officially, it is about protecting “national security,” preserving diplomatic relationships, or maintaining public order. In practice, classification can also mean sealing away decisions, proposals, and operations that would provoke outrage if exposed in real time.

For decades, citizens have speculated about what might be hiding behind blacked-out pages and sealed archives. Sometimes those suspicions turn out to be unfounded. Other times, declassified files reveal plans and actions that sound more like political thrillers than official policy memos.

Over the years, thousands of once-secret documents have been released into the public domain through declassification programs, freedom-of-information requests, and investigative reporting. Many shed light on some of the darkest chapters of the 20th century, particularly during the Cold War, when fear of communism and nuclear confrontation pushed governments into ethically murky territory.

From covert foreign interventions to surveillance of celebrities, from rejected false-flag proposals to long-buried war crimes, these files reveal that history is often more complicated—and sometimes more disturbing—than the public was initially told.

Here are ten dirty government secrets revealed by declassified files.

Related: 10 Shocking Secrets Tech Giants Tried to Hide

10 Katyn Massacre

In April 2010, Russia declassified Soviet-era files about one of the gravest massacres in its history—the Katyn Massacre. Between April and May 1940, more than 22,000 Polish officers were shot and killed by the Soviet secret police, the NKVD, at multiple execution sites including Katyn Forest. The documents included a letter from NKVD head Lavrenti Beria and a resolution signed by Joseph Stalin approving the executions. The move was widely seen as a gesture toward Poland after the 2010 Smolensk air crash that killed the Polish president on Russian territory.

According to some human rights groups, the release helped provide closure to victims’ families. However, sensitive materials identifying individual NKVD officers responsible for the killings were still withheld. The Katyn Massacre severely damaged diplomatic ties between the Soviet Union and the Polish government-in-exile during the Second World War.^[1]

9 Dalai Lama

Declassified documents released in the late 1990s revealed that the CIA ran a covert operation in Tibet between 1957 and 1969. The program aimed to arm and fund Tibetan resistance against Chinese rule. Tibetan guerrillas were trained in Nepal and at Camp Hale in Colorado. The operation reportedly included annual funding of approximately $1.7 million, along with a $180,000 annual subsidy for the Dalai Lama.

The documents detailed the CIA’s nearly decade-long involvement as part of a broader Cold War strategy to counter Chinese influence. The assistance ended in the early 1970s, when the Nixon administration moved toward diplomatic normalization with China.

Despite financial and logistical support, Tibetan guerrillas struggled to achieve most of their objectives. The declassified files add further context to Tibet-China relations, especially given China’s long-standing accusations that the Dalai Lama acted as an agent of foreign intelligence services.^[2]

8 Project Stargate

Project Stargate was a classified US government program that explored psychic and paranormal phenomena for military and intelligence purposes. It was launched in the early 1970s amid concerns that the Soviet Union was researching psychotronic warfare. The program focused on studying allegedly repeatable psychic phenomena that could potentially be used for espionage.

The project was led in part by parapsychologists Hal Puthoff and Russell Targ. It was initially known as Scanate—short for “scan by coordinate”—and early experiments in remote viewing were described internally as promising. This led to the program’s expansion under military oversight.

Participants attempted “remote viewing,” the practice of observing distant targets without physical presence. The research also examined psychoenergetics—the idea that individuals could interact with people or objects across time and space.

Although some internal reports described isolated successes, a later CIA-commissioned review concluded that the program produced no actionable intelligence of sufficient value. Project Stargate was officially terminated in 1995 after more than two decades of experimentation.^[3]

7 John Lennon

All intelligence files related to John Lennon were released in 2006 after a lengthy legal battle. The FBI agreed to make public the final documents following years of litigation by historians seeking access under the Freedom of Information Act. The files detailed the extent of surveillance against Lennon and other activists during the Vietnam War era.

The documents disclosed Lennon’s ties to New Left leaders and antiwar groups. They also noted his associations with activists such as Tariq Ali and Robin Blackburn. Despite earlier claims that releasing the files could provoke “military retaliation against the United States,” the documents contained no evidence of Lennon’s involvement in subversive or violent activity.

The FBI monitored Lennon closely because the Nixon administration feared he might mobilize young voters against President Richard Nixon during the 1972 election, particularly in support of Senator George S. McGovern.^[4]

6 Operation Northwoods

Operation Northwoods was the codename for a secret US military proposal in the early 1960s. Its objective was to generate public support for a war against Cuba. Drafted by senior military leaders, the plan included extreme measures. These ranged from staging violent incidents and sabotaging refugee boats to hijacking aircraft and orchestrating attacks in US cities that would be falsely attributed to Cuba. The goal was to manipulate public opinion and justify removing Fidel Castro from power following the failed Bay of Pigs invasion.

The proposal was presented to Secretary of Defense Robert McNamara in 1962 and was approved by the Joint Chiefs of Staff. However, it was rejected by civilian leadership and never implemented. The documents remained classified for decades before being declassified in the late 1990s through the efforts of the JFK Assassination Records Review Board.

A related initiative was Operation Mongoose, launched in November 1961 under President Kennedy, which aimed to destabilize Cuba through covert means. Unlike Northwoods, Mongoose was implemented in various forms.^[5]

5 Pegasus

It was later revealed that the FBI, under Director Christopher Wray, considered deploying the controversial Pegasus spyware for criminal investigations. Developed by the Israeli firm NSO Group, Pegasus is a zero-click tool capable of extracting extensive data from a target’s mobile phone without the user clicking on a link or taking any action. The FBI initially stated that it had purchased a license for research and development purposes. However, internal documents and court records indicated that the software was tested extensively between late 2020 and early 2021.

The controversy unfolded amid global concerns about Pegasus being misused by governments to surveil journalists, activists, and political opponents. Documents showed that in March 2021, the FBI’s Criminal Investigative Division recommended its potential use under specific conditions. Ultimately, the bureau did not deploy the tool operationally. Nevertheless, the declassified materials revealed how close the agency came to adopting one of the world’s most controversial surveillance technologies. Concerns remain that similar tools could emerge in the future for comparable investigative purposes.^[6]

4 Operation Gladio

Operation Gladio was a CIA-backed “stay-behind” network organized across Western Europe after the Second World War. Conceived in the 1950s, its primary purpose was to coordinate resistance in the event of a Soviet invasion of Western Europe. The operation’s existence was publicly disclosed in 1990 by Italian Prime Minister Giulio Andreotti, prompting widespread controversy. Since then, declassified materials and parliamentary investigations have provided additional details.

The network operated in multiple NATO countries, including Belgium, France, Greece, West Germany, and the Netherlands. Although initially focused on Allied nations, it extended to neutral countries such as Sweden and Switzerland by 1959. Investigations in Italy during the 1990s uncovered weapons caches that had been hidden for decades as part of the stay-behind structure.

Operation Gladio drew renewed scrutiny after links were alleged between elements of the network and far-right extremist activity in Italy during the 1970s. While the full scope of the operation’s activities remains debated, declassified files confirmed the existence of a coordinated Cold War-era clandestine network operating across Europe.^[7]

3 Indonesian Mass Killing of 1965–66

The years 1965 and 1966 marked one of the darkest periods in Indonesia’s history. A government-led anti-communist purge resulted in the deaths of hundreds of thousands, possibly up to a million, people. Declassified documents released in 2017 revealed that although Indonesian forces and paramilitary groups carried out the killings, several foreign governments—including the United States—were aware of and supported aspects of the campaign.

The files, originating from the US Embassy in Jakarta, covered events between 1963 and 1966. They described the Indonesian army’s systematic effort to eliminate members of the Indonesian Communist Party (PKI) and its suspected supporters. US assistance reportedly included providing communication equipment, financial support, and lists of communist officials.

The mass killings remain one of the largest episodes of violence in Indonesia’s modern history. In addition to the army, religious and civic groups were involved in the purge, and some clerics publicly framed the violence as a religious duty. The declassified files added further evidence of the international dimension surrounding the campaign.^[8]

2 Gulf of Tonkin Incident

The Gulf of Tonkin incident refers to naval confrontations between US forces and North Vietnam in August 1964. It is widely regarded as the catalyst for large-scale US intervention in the Vietnam War. The conflict ultimately led to the deaths of approximately 2 million Vietnamese civilians, more than 1 million North Vietnamese and Viet Cong soldiers, 250,000 South Vietnamese soldiers, and over 58,000 Americans.

Initially, US officials reported two separate attacks by North Vietnamese patrol boats against the USS Maddox and USS Turner Joy. However, nearly 200 National Security Agency documents declassified in the early 2000s revealed that the alleged second attack on August 4 likely never occurred. Intelligence was misinterpreted and presented as confirmation of hostile action.

President Lyndon B. Johnson used the reported incidents to secure public and congressional support for military retaliation. Congress quickly passed the Gulf of Tonkin Resolution, effectively granting the president broad authority to expand US military involvement in Vietnam. Later disclosures significantly altered the historical understanding of how the war escalated.^[9]

1 What Happened to Hideki Tojo?

Hideki Tojo served as Japan’s prime minister during much of the Second World War. After Japan’s surrender, he was tried by the International Military Tribunal for the Far East and executed in 1948 for war crimes. For decades, the precise location of his remains remained undisclosed. Authorities reportedly feared that revealing the burial site could turn it into a focal point for nationalist reverence.

In 2021, declassified US military documents uncovered by a Japanese historian clarified the mystery. Tojo’s cremated ashes, along with those of six other executed officials, were scattered from a US Army aircraft over the Pacific Ocean. The location was approximately 30 miles east of Yokohama, Japan.

The decision was intended to prevent the creation of a physical gravesite that could inspire ultra-nationalist movements in postwar Japan. Despite this, Tojo and several other convicted war criminals are enshrined symbolically at the controversial Yasukuni Shrine in Tokyo, where their legacy continues to spark political tensions.^[10]