In December 2016, diplomats and CIA officers at the US Embassy in Havana began to report mysterious symptoms. Dozens were suddenly and without warning falling ill with headaches, fatigue, hearing and vision loss, severe and debilitating cognitive impairment, tinnitus, brain fog, vertigo, and loss of motor control. Since then over 200 more diplomats, spies, DOD, and NSC personnel, from US embassies around the world and at home, have experienced some or all of this cluster of symptoms. 

This mysterious malady is known as Havana Syndrome. Now numbering over 200 cases, Havana Syndrome is affecting US officials in Europe, Asia, Australia, and the Americas. Its effects are complex, painful, and inconsistent. Victims describe being bombarded by waves of pressure in their heads or hearing the noise of an immense swarm of cicadas filling their heads. Others portray the effects as a wall of sound, in one place but not another, as if they are deliberately targeted. Most recently, in January 2020 a pair of National Safety Council staffers experienced symptoms just outside the White House, with one telling Adam Entous of The New Yorker that when it hit, he felt “as if I was going to die.” 

For the past four years, US intelligence agencies, the Departments of State and Defense, the White House, and governmental and non-governmental medical experts have been analyzing the data, looking for the root cause of Havana Syndrome. A major issue is that symptoms and severity differ from person to person, plus there is little rigorous data. Information shared between government agencies and medical institutions has lacked uniformity, leading to skepticism about the efficacy of these claims. Although government officials publicly call Havana Syndrome “anomalous health incidents,” major media outlets label them attacks--and it seems that top officials privately refer to them as attacks as well. Spokespeople for the State Department, Pentagon, and White House seem wary of antagonizing geopolitical rivals without proof.

As more information comes to light and medical studies are completed, two distinct positions on the causes of Havana Syndrome are emerging. Dominant schools of thought stem from reactions to two reports both published in 2020, one by the National Academies of Science, Engineering, and Medicine and the other by the Journal of the American Medical Association(JAMA). The 2020 National Academies report concluded that there were four plausible attack vectors on US officials: directed radio-frequency energy, chemicals, infectious agents, and psychological and social factors. The JAMA report reached similar conclusions. Both reports gave credence to the phenomenon but also cautioned that lack of scientific evidence limits conclusions and that each potential cause is speculative. 

Of the four plausible attack vectors identified in the JAMA and National Academies reports, directed energy weapons were deemed the most plausible. This school of thought is supported by former government officials such as John Bolton, Mark Esper, and several unnamed Biden Administration top advisors. Recently, while not explicitly endorsing a particular theory CIA Director William Burns emphasized the “very strong possibility” that Havana Syndrome is the result of intentional attacks, in a recent interview with NPR. Current or former US government scientists who have worked on biotechnology and security programs likewise support them. In a June 2021 article in The (London) Guardian, James Giordano, a professor of neurology and ethics at Georgetown University and a senior fellow in biotechnology, biosecurity and ethics at the US Naval War College, explained how the United States built prototypes of portable microwave weapons in 2004 but abandoned them due to ethical concerns, such as testing on humans or animals. But other countries such as China and Russia continued to work on long term directed energy weapon research and development. Another expert on microwave energy and biological effects, James Lin of the University of Illinois, points out how development of the technology has reached a point where it is such a weapon could be scaled to fit into a van or SUV. A technology pioneered by the Russians in the 1970s, these new weapons now have possible ranges of 500 to 1,000 yards.

The tentative conclusions from the 2020 JAMA and National Academies reports also yield skepticism in both the US federal government and the civilian scientific community. The main detractors from the theory of directed energy weapons are the FBI as well as neurologists and bioengineers at King’s College London and the University of Pennsylvania. After the first set of cases, the FBI dispatched a team to investigate. In a presentation to State Department officials, the team concluded that the victims were suffering from a mass psychogenic illness, where individuals experience neurological symptoms with no physical or environmental explanation. But as reported by Adam Entous of The New Yorker, the FBI had based its conclusions on secondary source material and had not directly spoken to any of the victims directly. Outside of the US federal government, Kenneth Foster of the University of Pennsylvania, and Peter Zimmerman of King’s College refuted the directed energy hypothesis as implausible.

While there are many public debates between the two positions, not everyone has access to the same primary sources and data points on Havana Syndrome. Due to security clearances issues and inter-agency “stove-piping,” where data is only shared within a single organization’s hierarchy and bypasses outside vetting, evaluation of data is limited to certain experts and organizations. And some civilian scientists lack clearances altogether. Another limiting factor is the need to safeguard US employees’ medical privacy, as well as protect the identity of CIA officers who work under cover.

Cases of Havana Syndrome keep cropping up--the most recent were reported in Vienna in July 2021--and yet we are still left with only plausible hypotheses regarding causes. Due to a lack of concrete evidence, neither the directed energy weapon theory nor any proposed alternatives can be proven or disproven, leaving those suffering from the syndrome with only post-symptom treatments. All that is clear is the very real and severe pain that more than 230 US diplomats, CIA officers, and other national security personnel are still experiencing.