The US House of Representatives recently passed a bill to help diplomats and officials that have been impacted by 'Havana Syndrome'. This legislation has already passed the Senate, and since signed into law by Biden.

According to The NY Times:

Since 2016, diplomats, intelligence officers and military personnel in Asia, Europe and the Americas have reported hearing strange sounds, feeling unexplained heat or experiencing pressure and then suffering headaches, nausea, vertigo or other symptoms. In many cases, the symptoms have gone on for months or years.

While some government officials are convinced that a hostile intelligence service using an eavesdropping device or a directed-energy weapon is responsible for the injuries, C.I.A. analysts have not reached a conclusion about what is causing the episodes or if a hostile power is responsible.

Directed energy weapons that, once exposed, cause lingering mental health problems for years? And it's happening all over the world, but no one knows who's doing it or if it's even physically possible? This sounds like a bad action movie premise.

What does the evidence say about the existence of Havana Syndrome?

Update March 1 2023: Washington Post reports that it is "very unlikely" that these symptoms were caused by an enemy wielding a secret weapon:


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    This question is probably a duplicate of an earlier one from 2017 that, unfortunately, didn't really see a properly sourced answer. For what it's worth, there's also a Wikipedia article on 'Havana syndrome'.
    – Schmuddi
    Commented Oct 4, 2021 at 20:09
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    Probably difficult to answer unless before/after brain scans would have fortuitously been taken and show something significant. Otherwise replicating such experiments on purpose would definitely be unethical, assuming they even have some idea what the "directed energy weapon" was. There is one imaging study that however used other people as controls ncbi.nlm.nih.gov/pmc/articles/PMC6652163 Commented Oct 4, 2021 at 23:55
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    This question is hindered by the meta-level question: What does it mean for a syndrome to exist? Just the correlation of some symptoms?
    – Oddthinking
    Commented Oct 5, 2021 at 1:29
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    There is a slight mis-match between the title and the body. There are two layers to this a) does Havana syndrome exist (i.e. are there people experiencing physiological symptoms), and b) was it caused by a directed energy weapon. It might be useful to resolve/clarify the scope of this question
    – Dave
    Commented Oct 5, 2021 at 16:05
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    The best part about this is that if it is caused by EM weapons, the best protection against conspiracy might finally be ye old tin foil hat!
    – svidgen
    Commented Oct 6, 2021 at 18:19

3 Answers 3


Are Directed-Energy Weapons Behind the Havana Syndrome?

In 2020, a study on Havana syndrome by the U.S. National Academies of Sciences, Engineering and Medicine concluded that the more than 130 victims experienced some real physical phenomena, and that the cause was most likely some form of electromagnetic radiation.
Perhaps the best option to prevent further attack is detection. It is relatively simple and inexpensive to install sensors to detect electromagnetic waves on buildings and vehicles. Such sensors could also help identify the location of the source of the attacks and, in this way, act as a deterrent.

The writer does not say why this simple and inexpensive option has not been tried.

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    So basically it exists in the same way as the Gulf War syndrome exists, i.e. bunch of people have some symptoms. As for the cause... we still don't know much about the Gulf one after decades of research. Commented Oct 5, 2021 at 6:04
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    @Abdullah any number of reasons, from "payback for those pesky sanctions" to "accidental side-effect of our crude eavesdropping equipment" Commented Oct 5, 2021 at 8:58
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    FWTW, the CIA guys haven't been exactly silent on this gq.com/story/cia-investigation-and-russian-microwave-attacks Commented Oct 5, 2021 at 12:10
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    @Obie2.0 - just speculating here, obviously, but I can sort of see that using such a thing against CIA operatives would be considered part of the rough and tumble of espionage; using it against diplomats and civil servants would be an act of outright (if sneaky) hostility; but using it against high-level, elected representatives of government would almost certainly be considered an act of war. I have literally nothing to back that up, but it makes sort-of-sense to me.
    – Spratty
    Commented Oct 5, 2021 at 15:41
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    @JBentley At least for most things like embassies and such, EM detection devices are already fitted. I know because I write firmware for them. But, of course, whether that would detect whatever this is would depend on, well, what it is. In particular, whether it's within the frequency range of the detection devices if it's EM. (The existing EM detection devices are mostly for detecting radio transmissions, i.e. to detect bugging devices.)
    – reirab
    Commented Oct 5, 2021 at 16:41

Maybe. Opinions differ and the evidence is inconsistent.

BBC News has recently produced a radio documentary about this, I've summarised it below (although it's worth listening to the audio, it's interesting).

At least some of the claimed instances are likely psychogenic or have 'normal' causes (eg food poisoning):

Some instances may be unrelated. "We had a bunch of military folk in the Middle East who claimed to have this attack - turned out they had food poisoning," says one former official. "We need to separate the wheat from the chaff," reckons Mark Zaid, who says members of the public, some with mental health issues, approach him claiming to suffer from microwave attacks. One former official reckons around half the cases reported by US officials are possibly linked to attacks by an adversary. Others say the real number could be even smaller.

A December 2020 report from the US National Academies of Sciences concluded that evidence exists to support the existence of 'Havana Syndrome':

A December 2020 report by the US National Academies of Sciences was a pivotal moment. Experts took evidence from scientists and clinicians as well as eight victims. ... The panel looked at psychological and other causes, but concluded that directed, high energy, pulsed microwaves were most likely responsible for some of the cases, similar to the view of James Lin, who gave evidence.  

But the US State Department, which sponsored the report, considers it 'only a plausible hypothesis':

But even though the State Department sponsored the study, it still considers the conclusion only a plausible hypothesis and officials say they have not found further evidence to support it.

New evidence is emerging:

The BBC has learnt that new evidence is arriving as data is collected and analysed more systematically for the first time. Some of the cases this year showed specific markers in the blood, indicating brain injury. These markers fall away after a few days and previously too much time had elapsed to spot them. But now that people are being tested much more quickly after reporting symptoms, they have been seen for the first time.  

The answer may be complex and multi-faceted:

The debate remains divisive and it is possible the answer is complex. There may be a core of real cases, while others have been folded into the syndrome. Officials raise the possibility that the technology and the intent might have changed over time, perhaps shifting to try and unsettle the US. Some even worry one state may have piggy-backed on another's activities. "We like a simple label diagnosis," argues Professor Relman. "But sometimes it is tough to achieve. And when we can't, we have to be very careful not to simply throw up our hands and walk away."

Source: ‘Havana syndrome ’ and the mystery of the microwaves, Gordon Corera, BBC News, 9 September 2021

See also: The mystery of Havana syndrome (27 mins audio, documentary podcast from BBC News), 9 September 2021



Your question is pretty much exactly my reaction the first time I heard of this, especially "This sounds like a bad action movie premise". It is difficult to research objectively because different theories to explain the incidents implicate a different set of sources as unreliable. What I can say after some research is that, yes, this is a legit story, and no, it is not a crazy conspiracy theory where the editors of the NY Times made a mistake and published something that should have been in Weekly World News.

Other answers on this forum have already given good summaries of what evidence is out there with numerous sources.
All I would add is that, for a single source that is a detailed composite summary from a more reliable source than a public forum or Wikipedia, you should start with the assessment by the National Academy of Sciences (you can click "read online" without creating an account or purchasing anything):

An Assessment of Illness in U.S. Government Employees and Their Families at Overseas Embassies (2020)

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