Operation Denver (sometimes referred to as "Operation INFEKTION" from was an active measure disinformation campaign run by the KGB in the 1980s to plant the idea that the United States had invented HIV/AIDS as part of a biological weapons research project at Fort Detrick, Maryland. Historian Thomas Boghardt popularized the codename "INFEKTION" based on the claims of former East German Ministry for State Security (Stasi) officer , who claimed that the Stasi codename for the campaign was either "INFEKTION" or perhaps also "VORWÄRTS II" ("FORWARD II"). However, historians Christopher Nehring and Douglas Selvage found in the former Stasi and Bulgarian State Security archives materials that prove the actual Stasi codename for the AIDS disinformation campaign was Operation Denver. The operation involved "an extraordinary amount of effort – funding radio programs, courting journalists, distributing would-be scientific studies", and even became the subject of a report by Dan Rather on the CBS Evening News.

The Soviet Union used the campaign to undermine the United States' credibility, foster anti-Americanism, diplomatically isolate the U.S. abroad, and create tensions between host countries and the U.S. over the presence of American military bases, which were often portrayed as the cause of AIDS outbreaks in local populations.

Story genesis and progression The groundwork appeared in the pro-Soviet Indian newspaper Patriot, which, according to a KGB defector named Ilya Dzerkvelov, was set up by the KGB in 1962 with the sole purpose of publishing disinformation. An anonymous letter was sent to the editor in July 1983 from a "well-known American scientist and anthropologist" who claimed that AIDS was manufactured at Fort Detrick by genetic engineers. The "scientist" claimed that "that deadly mysterious disease was believed to be the results of the Pentagon's experiments to develop new and dangerous biological weapons", and implicated Centers for Disease Control and Prevention (CDC) scientists sent to Africa and Latin America to find dangerous viruses alien to Asia and Europe. These results were purportedly analyzed in Atlanta and Fort Detrick and thus the "most likely course of events" leading to the development of AIDS. The letter claimed that The Pentagon was continuing such experiments in neighboring Pakistan and as a result, the AIDS virus was threatening to spread to India. The title of the article, "AIDS may invade India", suggested that the immediate goal of the KGB's disinformation was to exacerbate tensions between the U.S., India, and Pakistan.

Two years later, the KGB apparently decided to make use of its earlier disinformation to launch an international campaign to discredit the U.S. They wrote in a telegram to their allied secret service in Bulgaria, the Bulgarian Committee for State Security (KDS) on September 7, 1985:We are conducting a series of [active] measures in connection with the appearance in recent years in the USA of a new and dangerous disease, "Acquired Immune Deficiency Syndrome – AIDS"…, and its subsequent, large-scale spread to other countries, including those in Western Europe. The goal of these measures is to create a favorable opinion for us abroad that this disease is the result of secret experiments with a new type of biological weapon by the secret services of the USA and the Pentagon that spun out of control.The telegram, which referred indirectly back to the Patriot article ("facts ... in the press of the developing countries, in particular India"), provided guidance to Bulgarian State Security regarding how to couch their AIDS disinformation: Facts have already been cited in the press of the developing countries, in particular India, that testify to the involvement of the special services of the United States and the Pentagon in the appearance and rapid spread of the AIDS disease in the United States, as well as other countries. Judging by these reports, along with the interest shown by the U.S. military in the symptoms of AIDS and the rate and geography of its spread, the most likely assumption is that this most dangerous disease is the result of yet another Pentagon experiment with a new type of biological weapon. This is confirmed by the fact that the disease affected initially only certain groups of people: homosexuals, drug addicts, immigrants from Latin America. A month later, the Soviet newspaper Literaturnaya Gazeta, also a known outlet for KGB disinformation, published an article from Valentin Zapevalov entitled, "Panic in the West, or what is hiding behind the sensation surrounding AIDS". It cited the (dis)information contained in the Patriot article, but also gave further details regarding the alleged development of the AIDS virus. Employees of the CDC had allegedly assisted the Pentagon by traveling to Zaire, Nigeria and Latin America to collect samples of the "most pathogenic viruses" that could not be found in Europe or Asia. These samples were then combined to develop the human immunodeficiency virus (HIV) that causes AIDS. The disinformation campaign insisted the Pentagon then carried out isolated experiments in Haiti and within the U.S. itself on marginalized groups in U.S. society: drug addicts, homosexuals, and the homeless. Zapevalov's article was subsequently reprinted in Kuwait, Bahrain, Finland, Sweden, Peru, and other countries. It followed very closely the guidelines that the KGB had already sent to its Bulgarian "comrades" a month before.

Stasi involvement in the disinformation campaign Determining the exact role of the Stasi in the AIDS disinformation campaign has been difficult, given that around 90% of the records of its foreign intelligence division, the Main Directorate for Reconnaissance (HVA) were destroyed or disappeared in 1989–90. Based on materials in the Bulgarian secret police archives, the card files of the HVA, and documents from or relating to the HVA scattered among the records of other divisions of the Stasi, it has been possible to reconstruct some aspects of the Stasi's involvement in the disinformation campaign. At the beginning of September 1986, the tenth division of the HVA (HVA/X), responsible for organizing and coordinating the HVA's campaigns of active measures, wrote the following in a draft plan for cooperation with Bulgarian State Security:Operation "DENVER". With the goal of exposing the dangers to mankind arising from the research, production, and use of biological weapons, and also in order to strengthen anti-American sentiments in the world and to spark domestic political controversies in the USA, the GDR [German Democratic Republic] side will deliver a scientific study and other materials that prove that AIDS originated in the USA, not in Africa, and that AIDS is a product of the USA’s bioweapons research. The KGB confirmed that the East German HVA was playing a central role on various occasions, including in a telegram to the Bulgarians in 1987:The AIDS issue

A complex of [active] measures regarding this issue has been carried out since 1985 in cooperation with the [East] German and to some extent the Czech colleagues. In the initial stage, the task was resolved of spreading in the mass media the version regarding the artificial origin of the AIDS virus and the Pentagon’s involvement in by means of the military-biological laboratory at Fort Detrick.

As a result of our joint efforts, it was possible to widely disseminate this version.

The Segal Report As noted above, the Stasi's HVA/X had written that it would send its Bulgarian "comrades" a "scientific study" allegedly "proving" that "AIDS is a product of the USA's bioweapons research". From the context of the discussions between officers of the HVA/X and their Bulgarian counterparts in mid-September 1986, it was clear which study was meant: "AIDS: Its Nature and Origin" by Soviet-East German biologist Jakob Segal and his wife, Lilli Segal. The study had been distributed at the summit meeting of the Non-Aligned Movement in August–September 1986 in a brochure entitled, "AIDS: USA home-made evil, NOT out of AFRICA". The report was quoted heavily by Soviet propagandists, and the Segals were often said to be French researchers to hide their connections to communism. Although both Segals, given the double danger to them as Jews and members of the Communist Party of Germany, had fled into exile in France in 1933, both had attained Soviet citizenship in 1940 on the basis of Jakob's birth in then Soviet-annexed Lithuania, and in 1953, they had returned to Germany—specifically, to communist East Berlin.

In his report, Segal postulated that the AIDS virus was synthesized by combining parts of two distantly related retroviruses: VISNA and HTLV-1. An excerpt of the Segal Report reads as follows:

Elsewhere in the report, Segal said that his hypothesis was based purely on assumptions, extrapolations, and hearsay and not at all on direct scientific evidence.

The exact relationship of both Segals to the KGB, Stasi, or both at this time—to the extent that it existed—remains unclear. Both publicly denied any involvement of the KGB or Stasi in their work. The Deputy Director of HVA/X, Wolfgang Mutz, hinted that the HVA had played a role in the publication—or actually, the photocopying—and distribution of the Harare brochure in talks with Bulgarian State Security in September 1986. He also suggested that the "operational division" of the HVA with which HVA/X had been cooperating in the disinformation campaign had somehow "attracted" Segal to his research.

This "operational division" was in fact an office in the Sector for Science and Technology (Sektor Wissenschaft und Technik, SWT) of the HVA, responsible for intelligence-gathering on AIDS and genetic engineering (HVA/SWT/XIII/5). This office had registered a "security dossier" (Sicherungsvorgang, SVG) "Wind" on September 6, 1985, regarding the protection of East German scientists in the areas of AIDS research, genetic engineering and biotechnology from outside "attacks" in the form of espionage or manipulation by foreign agents. This office in HVA/SWT apparently registered both Segals in this dossier as "contact persons" under the codename "Diagnosis"; whenever other divisions of the Stasi inquired about the Segals, they were directed to this office. HVA/SWT—or "the security", as Jakob Segal called them—gave him at least one piece of advice regarding his study before its printing and distribution. Whether Segal listened to this advice remains unclear. Still, given their official designation as "contact persons", they need not have known, at least officially, that they were dealing with the Stasi, although Jakob Segal likely knew or could have guessed, given his past dealings with both the Stasi and the KGB. It is quite possible that HVA/SWT was already coordinating with the KGB regarding Segal's research—even without his knowledge—in the second half of 1985, at the time that "Wind" was registered. Nevertheless, none of the Stasi officers involved with "Wind" or Operation "DENVER" ever claimed that the HVA had played a role in drafting Segal's study. It was clearly his own work, in cooperation with his wife Lilli, although he knew and expected that it would be used for "propaganda".