File 028 · 2016–today · Mystery illness

Havana Syndrome

Since 2016, US diplomats and officials reported sudden dizziness, pain and cognitive problems. Agencies disagree about whether a foreign directed-energy weapon is a plausible cause.

Background

In late 2016 staff at the US embassy in Havana began reporting a sudden loud sound or sensation of pressure followed by headaches, dizziness, hearing problems and difficulty concentrating. Canadian diplomats in Cuba reported similar symptoms. Later cases were reported from China, Europe, Asia and the United States itself, now officially called 'anomalous health incidents'.

The condition drew several theories at once: a sonic weapon, microwave radiation, a pesticide, psychological factors or a mix of unrelated illnesses. The US government has investigated for years, through the intelligence agencies, the National Academies and health researchers.

What the record shows

• The symptoms reported by many people are real and several affected staff received medical care and compensation under US law.
• The 2020 National Academies report said the available evidence could not rule out directed energy as a cause in some cases.
• The intelligence community's 2023 and 2025 assessments concluded that most cases were likely caused by other factors such as existing medical conditions, stress and environmental causes, and found no evidence that a foreign power used a weapon.
• The 2024 NIH studies did not find the brain injuries that some researchers had expected.

Timeline

• Late 2016 First reports at the US embassy in Havana.
• 2017 Similar cases are reported in Guangzhou, China.
• Dec 2020 A National Academies report says directed pulsed radio-frequency energy appears the most plausible mechanism for some cases.
• Mar 2023 A US intelligence assessment says it is 'very unlikely' that a foreign adversary is responsible for most cases.
• Mar 2024 Two NIH studies find no clear evidence of brain injury in affected personnel compared to controls.
• Jan 2025 An updated assessment keeps that conclusion; two agencies express low confidence in a possible foreign role in a limited number of cases.
• 2025–26 Congress and the director of national intelligence review earlier analyses; reporting says two earlier intelligence reports were withdrawn in June 2026.

Checking the claims

The claim: a foreign government attacked US personnel with a secret weapon. What has been established: people were sick, and some may have had genuine injuries. What has not been shown is a device, a delivery method or a perpetrator. The agencies' main conclusion for most cases is that no foreign weapon was involved.

The disagreement is partly about method. Agencies judged incidents on a case-by-case basis, and a small number remain unexplained. Critics argue the intelligence analysis was too dismissive and that victims have been poorly served. Skeptics argue that the cases are better explained by ordinary illness, noise from insects or equipment, and the anxiety of working in tense environments. Both views are still being argued.

Claimed, but not shown

Allegations that a specific country used a microwave or sonic weapon have not been proven in public evidence. Allegations that all cases are psychological are also not established.

Verdict

Sources

• National Academies of Sciences, Engineering, and Medicine, An Assessment of Illness in U.S. Government Employees and Their Families at Overseas Embassies (2020)
• Office of the Director of National Intelligence, assessments of anomalous health incidents (2023 and 2025 updates)
• NIH studies on affected US government personnel, JAMA (March 2024)

Connected files (red threads)

• HAARP and weather control — Directed-energy theories link the two
• Project Stargate: the CIA's psychic spies — Another government effort to study unexplained effects on the mind

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