At the end of 2016, employees of the US Embassy in Havana began complaining of dizziness, nausea, headaches, and hearing problems. Some claimed that before their condition worsened, they heard piercing or low-frequency sounds, and the impact itself felt directed. Initially, these complaints were not taken seriously, but by 2017 it became clear that these were not isolated cases, but a new, unknown symptom that later became known as “Havana syndrome.”
According to official data, 26 American diplomats and their family members were affected in Havana alone. Some of the staff were evacuated, while others were deemed temporarily or permanently unfit for further service. The US State Department reduced the embassy staff, and Cuba found itself at the center of an international scandal. However, further developments showed that the “Havana syndrome” was not a local Cuban anomaly.
In 2018, similar symptoms were reported among US consulate employees in Guangzhou, China. Several diplomats were urgently sent to the US, where doctors found signs of mild traumatic brain injury similar to those caused by physical trauma rather than psychosomatic disorders. This moment became a turning point: the hypothesis of mass stress or “collective panic” began to lose credibility.
In subsequent years, the geography of the syndrome expanded. Cases were reported in Europe, Asia, and even Washington, D.C. Between 2019 and 2021, US mission staff reported symptoms in Frankfurt, Berlin, Tbilisi, and other cities. In Vienna, according to media reports, several dozen American diplomats and employees of international organizations were affected. Many of them complained of long-term effects: chronic headaches, cognitive decline, and sleep problems. For some of the victims, as after the events in Havana, this meant the end of their diplomatic careers.
Against the backdrop of a growing number of incidents, theories about the possible cause have emerged. One of the most widely discussed hypotheses is the use of directed energy, microwave, or acoustic technologies. In 2024, a joint investigation by The Insider, Der Spiegel, and 60 Minutes pointed to a possible link between cases of “Havana syndrome” and the activities of GRU Unit 29155, which had previously been involved in a number of foreign operations. Journalists compared the movements of officers from this unit with the locations and times of the incidents, and also drew attention to Russian military research into non-lethal weapons and their effects on the human nervous system.
An incident involving a CIA officer traveling in India in 2021 caused particular concern. The officer suddenly experienced symptoms characteristic of “Havana syndrome” and was evacuated urgently. This incident occurred on the eve of a visit by a high-ranking American official and, according to media reports, caused serious irritation and concern among CIA leadership. It was one of the factors that prompted the agency to reconsider its previous cautious stance.
The reaction of the American intelligence community has remained controversial over the years. Official reports from the CIA and other agencies have long emphasized that there is no direct evidence of hostile foreign influence, and that most cases can be explained by a combination of medical, psychological, and environmental factors. However, dissatisfaction with this approach grew within the system. Victims accused the leadership of ignoring the threat, and Congress accused it of insufficient transparency and protracted investigations.
Under pressure from the public and the victims themselves, the so-called Havana Act was passed in 2021, providing financial compensation and medical assistance to those affected by abnormal health incidents. The very fact that the law was passed was an indirect admission by the state that it acknowledges that this is a real and serious problem, rather than mass self-hypnosis.
By the mid-2020s, interest in the topic had grown dramatically. In 2024–2025, the American media reported that the Pentagon had acquired and was testing a device that could generate radiofrequency radiation associated with the symptoms of the syndrome, a portable device containing components of Russian origin. This prompted experts and intelligence officials to once again discuss the possible link between technology and neurological effects.
Although there is still no direct evidence of Russia’s involvement, such reports increase pressure on the US intelligence community to provide definitive answers. Whether that means confirming foreign interference or developing its own protective and preventive measures.
Today, “Havana syndrome” remains an unsolved mystery at the intersection of medicine, intelligence, and politics. Nearly a decade after the first reports, the question of its origin remains open, with hypotheses ranging from mystical microwave attacks to psychological and medical explanations. The real consequences, from the waste of resources on investigations to the deterioration of international relations, are already being felt. The CIA’s response, from initial skepticism to cautious reassessment, reflects a broader problem: that modern threats can be invisible, difficult to prove, but no less real for that. And that is what makes the “Havana syndrome” not only a medical and scientific phenomenon, but also an important political issue.