Intelligence Assessments & Government Inquiries

Official assessments of Havana Syndrome, generally referred to by the U.S. government as Anomalous Health Incidents (AHIs), have evolved substantially since the first cases were reported in 2016. In July 2026, the Department of War renamed its AHI Cross-Functional Team the Directed Energy Bio-Effects (DEBE) Cross-Functional Team as part of a renewed focus on non-kinetic threats. Scientific panels, intelligence agencies and congressional investigations have reached differing conclusions about possible causes. This page traces those assessments chronologically, distinguishing established evidence, analytical judgments and unresolved questions.

1. The Havana Incidents and the Beginning of the Investigation

In late 2016, U.S. Embassy personnel in Havana, Cuba, began reporting unusual episodes involving the sudden onset of symptoms. Accounts included head or ear pain, tinnitus, dizziness or vertigo, visual problems and, in some cases, cognitive difficulties. Some individuals described a loud or unusual sound perceived as coming from a particular direction. The incidents subsequently became widely known as “Havana Syndrome” and were later grouped by the U.S. government under the term Anomalous Health Incidents (AHIs).

The cause was not established. As reports accumulated, the U.S. government began medical, security and intelligence investigations. Similar incidents were subsequently reported by U.S. personnel in other countries and within the United States, substantially expanding the scope of the investigation.

A State Department Accountability Review Board later examined the government's initial response. Its 2018 review found serious organisational shortcomings, including inadequate coordination, communication problems and the absence of a senior official with overall responsibility for the response. Importantly, the investigation had not established what had caused the incidents or who, if anyone, was responsible.

U.S. Government Accountability Office — Havana Syndrome: Better Patient Communication and Monitoring of Key DOD Tasks Needed to Better Ensure Timely Treatment (2024)

https://www.gao.gov/products/gao-24-106593

U.S. State Department — Accountability Review Board: Havana, Cuba (2018, declassified copy)

https://nsarchive.gwu.edu/document/20672-havana-cuba-accountability-review-board-june-2018 

The second is a declassified State Department document hosted by the National Security Archive rather than a current State Department webpage.

2. The 2020 National Academies Assessment

In 2020, the National Academies of Sciences, Engineering, and Medicine published An Assessment of Illness in U.S. Government Employees and Their Families at Overseas Embassies, commissioned by the U.S. Department of State.

The committee examined the distinctive acute symptoms reported by some personnel, including the sudden perception of sound, sensations of pressure or vibration, ear or head pain, and symptoms that appeared spatially localized or directional. It evaluated several possible mechanisms, including directed radiofrequency energy, chemical exposure, infectious disease, and psychological or social factors.

The committee concluded that directed, pulsed radiofrequency energy appeared to be the most plausible mechanism for explaining the distinctive acute symptoms among the cases it considered. It found that several reported features were consistent with known RF effects, including perceived sounds and sensations of pressure, tinnitus, balance disturbance and the reported directionality of some episodes. 

However, this was a plausibility assessment, not proof that RF energy caused the incidents. The committee stressed major limitations in the available evidence. It lacked complete primary medical data, cases varied substantially, and there was insufficient information to connect particular RF exposure parameters with particular symptoms. Its task was explicitly not to “solve” what caused the illnesses, but to evaluate plausible mechanisms. 

The report therefore represents an important scientific assessment supporting the plausibility of directed pulsed RF energy, while leaving the actual cause, source and attribution of the incidents unresolved.

National Academies of Sciences, Engineering, and Medicine (2020) — An Assessment of Illness in U.S. Government Employees and Their Families at Overseas Embassies

https://www.nationalacademies.org/units/HMD-BGH-18-07

3. The 2022 Intelligence Community Experts Panel

In 2022, the Office of the Director of National Intelligence and the CIA released findings from an Intelligence Community Experts Panel assembled to investigate potential mechanisms behind Anomalous Health Incidents. The multidisciplinary panel reviewed more than 1,000 classified documents, incident reporting, medical records and scientific and intelligence information. Its task was to examine possible mechanisms, not determine who might have been responsible. 

The panel concluded that the reported signs and symptoms were genuine and compelling and that a subset of incidents could not readily be explained by known environmental or medical conditions. For this subset, it found that pulsed electromagnetic energy, particularly in the radiofrequency range, could plausibly explain the core characteristics, although significant information gaps remained. Ultrasound was also considered plausible, but only in circumstances involving close access. 

Importantly, this did not establish that RF energy had actually been used. Nor did the panel identify an attacker or attribute the incidents to a foreign government. Its findings concerned whether proposed physical mechanisms were technically capable of producing characteristics resembling those reported in a subset of cases. 

This distinction would become increasingly important. Scientific and technical assessments could regard an RF mechanism as plausible while intelligence assessments examining attribution—whether evidence connected an adversary to actual incidents—could reach a different conclusion.

CIA — Intelligence Community Experts Panel on Anomalous Health Incidents (2022)

https://www.cia.gov/stories/story/statement-from-dni-haines-and-dcia-burns/

Official statement on the panel's findings

4. The 2023 Intelligence Community Assessment

On 1 March 2023, the U.S. Intelligence Community published an updated assessment examining whether one or more foreign actors were responsible for AHIs reported by U.S. government personnel since 2016.

Most Intelligence Community agencies assessed that it was “very unlikely” that a foreign adversary was responsible for the reported incidents, although agencies expressed different levels of confidence. Two agencies instead assessed foreign responsibility as “unlikely” with low confidence. Investigations had not identified an adversary responsible for any incident, and the assessment reported no credible evidence that a foreign adversary possessed a weapon or collection device causing AHIs. 

The assessment did not, however, amount to a unanimous conclusion that radiofrequency energy was physically incapable of producing such effects. Two agencies judged deliberate causal mechanisms “unlikely” rather than “very unlikely” and did so with low confidence because they considered RF energy a plausible cause, drawing partly on the 2022 IC Experts Panel and research by U.S. laboratories. 

This distinction is central to interpreting the assessment. The Intelligence Community was primarily evaluating whether the available evidence connected reported incidents to a foreign adversary and deliberate external mechanism. That is a different question from whether pulsed RF energy is scientifically capable of producing particular biological or auditory effects.

The 2023 assessment therefore substantially weakened the case for a coordinated foreign campaign based on the intelligence then available, while leaving some technical questions about RF mechanisms open. 

CIA — Statement by Director William J. Burns on the Intelligence Community Assessment on AHIs (2023)

Read the official CIA statement

https://www.cia.gov/stories/story/statement-cia-director-burns-on-ic-assessment-ahis/

5. The 2025 Intelligence Community Update

On 10 January 2025, the U.S. Intelligence Community issued another updated assessment after reviewing new intelligence, scientific research and information concerning foreign weapons development.

Most Intelligence Community components retained the central 2023 judgment that it was “very unlikely” a foreign actor was responsible for the events reported as possible AHIs. Five components continued to emphasise intelligence reporting pointing away from foreign involvement, investigations of key incidents and assessments of foreign research and weapons programmes. 

However, the update contained an important change. One IC component judged there was a “roughly even chance” that a foreign actor had used a novel weapon or prototype device to harm a small, undetermined subset of affected U.S. personnel or dependants. A second component judged there was a “roughly even chance” that a foreign actor had developed a device capable of causing such effects, although that component continued to assess that deployment in reported incidents was unlikely. Both judgments were made with low confidence. 

The two components shifted their assessments because of reporting they interpreted as showing progress by foreign actors in relevant scientific research and weapons development. The remaining components did not consider the new information sufficient to alter their previous conclusions. 

The 2025 assessment therefore did not overturn the Intelligence Community's majority position. It did, however, make the overall picture more nuanced: most components continued to assess foreign involvement as very unlikely, while two components became less certain about whether a foreign actor possessed—or, in one component's judgment, may have used—a novel capability against a small subset of cases.

Office of the Director of National Intelligence — Updated Assessment of Anomalous Health Incidents, as of December 2024 (10 January 2025)

6. The 2026 Directed Energy Bio-Effects (DEBE) Cross-Functional Team

On 10 July 2026, the U.S. Department of War announced that its Anomalous Health Incidents Cross-Functional Team had been officially renamed the Directed Energy Bio-Effects (DEBE) Cross-Functional Team. The team operates under the Office of the Under Secretary of War for Research & Engineering. 

According to the Department, the change forms part of a more dedicated warfighter and medical focus on non-kinetic threats, alongside expanded interagency collaboration and coordinated research. The Department also stated that it would continue to emphasise scientific integrity, validated outcomes and care for affected personnel. 

The terminology is significant because it explicitly places directed-energy biological effects at the centre of the team's mission. However, the announcement does not state that directed energy has been established as the cause of every incident previously classified as an AHI, nor does it identify a particular weapon or foreign actor.

The development is therefore best understood as an important change in the U.S. government's investigative and research framework, rather than proof of a final causal or attribution judgment.

U.S. Department of War (10 July 2026) — Establishment of the Directed Energy Bio-Effects Cross-Functional Team

DefenseScoop — Pentagon rebrands AHI team as Directed Energy Bio-Effects CFT

https://defensescoop.com/2026/07/13/havana-syndrome-payments-directed-energy-bio-effects/

7. What Do The Government Assessments Actually Tell Us?

Taken together, the official assessments do not produce a single simple conclusion. Part of the apparent disagreement arises because different investigations were answering different questions.

The 2020 National Academies assessment examined possible mechanisms capable of explaining the distinctive acute symptoms reported in some cases. It identified directed, pulsed radiofrequency energy as the most plausible mechanism among those it considered, while emphasising significant evidentiary limitations.

The 2022 Intelligence Community Experts Panel also examined mechanisms rather than attribution. For a subset of incidents it considered difficult to explain through known environmental or medical conditions, the panel concluded that pulsed electromagnetic energy—particularly radiofrequency energy—could plausibly account for the core characteristics.

The 2023 Intelligence Community assessment addressed a different question: whether the accumulated intelligence supported the involvement of a foreign adversary. Most agencies judged foreign responsibility very unlikely, although two agencies retained greater uncertainty and continued to regard RF energy as a plausible causal mechanism.

The 2025 update preserved the majority assessment while increasing uncertainty within two Intelligence Community components. One judged there was a roughly even chance that a foreign actor had used a novel weapon or prototype device against a small, undetermined subset of affected personnel or dependants; another judged there was a roughly even chance that a foreign actor had developed a relevant capability. Both judgments were made with low confidence.

Finally, the establishment of the Directed Energy Bio-Effects Cross-Functional Team in 2026 demonstrates continued U.S. government interest in directed-energy biological effects and non-kinetic threats.

The evidence therefore supports keeping three questions separate: Can a proposed mechanism produce relevant effects? Was that mechanism actually present during a particular incident? If so, who was responsible? Evidence supporting one of these propositions does not automatically establish the others.

8. Sources & Official Documents