Before Havana Syndrome, There Was Moscow Signal

Today’s Havana syndrome is “like déjà vu all over again,” as Yogi Berra might have put it.


In 1960, U.S. Representative to the United Nations Henry Cabot Lodge Jr. points to the spot on the U.S. Great Seal (a 1945 gift from the Soviets that hung in Spaso House for decades) where it had been bugged, providing proof of Soviet espionage to the U.N. Security Council. The Theremin device inside was activated by external electromagnetic signals, making it difficult to detect.
Bettmann / Getty

In December 2016, just as the Obama administration was leaving office, strange reports began coming from our embassy in Havana, Cuba. People were exhibiting peculiar symptoms, including migraines, dizziness, memory loss, brain fog and an inability to perform normal functions at work. Often, the initial onset of symptoms was accompanied by clicking sounds.

At first, when the symptoms were confined to a few Americans and Canadians serving in Havana, these reports were treated with skepticism. While the State Department drew down its staff at Embassy Havana, and some officials hinted darkly that we were under some sort of foreign attack, others were much more sanguine. Armchair psychiatrists and “experts” who had never met the victims or diagnosed their illness in a professional setting leaned to the theory that it was all a “psychogenic illness”—in other words, people had symptoms, but the stresses and strains of work were the cause, and they were imagining themselves into sickness. There were even theories that a certain type of Cuban cricket was triggering this “mass hysteria” with its peculiarly loud call.

These theories all came a cropper, however, when reports of what soon came to be called “Havana syndrome” gradually spread to other embassies around the world, always seeming to affect embassy officials and their families away from work, in public places, or in apartments and hotel rooms. By 2021, more than 200 persons had been affected.

The victims of what the U.S. government is now calling “anomalous health incidents,” particularly those who were State Department employees, began to feel that their complaints were not being taken seriously, and that they were being met with indifference and even disbelief. Some had trouble getting medical treatment. Other agencies, such as the CIA, approached the problem more seriously, but generally the U.S. government’s approach was disunited. Eventually Congress got involved, notably Senators Susan Collins (R-Maine) and Jeanne Shaheen (D-N.H.) and Congressman Adam Schiff (D-Calif.), passing the HAVANA Act (Helping American Victims Afflicted by Neurological Attacks), which mandated that persons who suffer from Havana syndrome should be treated as if they were wounded veterans, which in fact they are.

In December 2020 the National Academies of Sciences, Engineering, and Medicine published an analysis of Havana syndrome, “An Assessment of Illness in U.S. Government Employees and Their Families at Overseas Embassies,” concluding that the most likely cause was microwaves. The symptoms fit, as did the reports of the victims. But this conclusion could not be reached with certainty due to a lack of physical evidence. Moreover, there was a more basic question that needed to be asked: If microwaves were, indeed, the cause of Havana syndrome, someone had to be beaming them at our people. If that was true, who was doing it and why? Those questions remain unanswered to this day.

Echoes of Moscow Signal

As I followed the Havana syndrome story, it increasingly occurred to me that I had seen something like this before. The mention of the word “microwaves,” in particular, triggered a flood of memories, as did the stories of initial skepticism by the State Department and other agencies over the concerns of potential victims. It was Moscow Signal all over again.

The first use of microwaves to activate a bugging device in Spaso House, the ambassador’s residence, was discovered in 1951.

During the Cold War, the Soviets beamed microwaves at our embassy in Moscow for decades. It is uncertain exactly when it started, although the first use of microwaves to activate a bugging device in Spaso House, the ambassador’s residence, was discovered in 1951. There were other reports that the Soviets were beaming microwaves at Spaso House during Vice President Richard Nixon’s visit to Moscow in 1959. As for the embassy, once again, reports in the unclassified realm are spotty. It is known for sure that the Soviets were bombarding the upper floors of the central wing of the chancery in the 1960s, but it is equally possible that microwaves were used against the embassy much earlier than that (we moved into the chancery on Garden Ring Road in 1953).

One thing is certain: For years, our diplomats serving in Moscow were kept in the dark. This did not apply to the interagency community, however, which formed several groups to study the phenomenon and, apparently, to study our diplomats without their knowledge. Scientists at Johns Hopkins University’s Applied Physics Laboratory were assigned to oversee research into the phenomenon. Meanwhile, blood studies were reportedly done on Embassy Moscow personnel, who were not told about the microwaves, but given the cover story that “viral studies” were being conducted.

While the prevailing conclusion of all the studies was that microwaves were not harmful, a few scientists strongly objected—including Dr. Allan Frey (discoverer of the “Frey Effect,” which, among other things, noted that microwaves could cause people in the beam’s path to hear clicking sounds) and Dr. Robert Becker, who resigned his position because he believed the U.S. research program to be immoral. According to researcher Annie Jacobsen, in her book Phenomena (2017): “Becker’s government work convinced him that a microwave signal such as the Moscow Signal ‘could affect the central nervous system, put people to sleep, interfere with decision-making capacity and induce chronic stress.’ He believed that the Soviets had been ‘using embassy employees as test subjects for low-level EMR [electromagnetic radiation] experiments.’”

Why Keep It a Secret?

Good question, especially for those who were targeted. The biggest reason, most likely, was because the interagency community generally believed that microwaves were not harmful. And, of course, the longer secrecy was maintained, the more difficult it was to break. In addition, however, there were apparently diplomatic reasons for keeping the whole issue quiet. With the advent of détente in the early 1970s, no one was looking for an obstacle to diplomatic progress with the Soviets, which was accelerating under the Nixon administration.

Eventually, however, two factors required a reevaluation of this policy. First, the intensity of Moscow Signal began to increase, and a second source was detected, also aimed at the upper floors of the embassy. In January 1976 the Gerald Ford administration decided that Ambassador Walter Stoessel, then our chief of mission in Moscow, had to be briefed. For those who knew him, one can only imagine what was going through his mind when he received the news. Stoessel was a diplomat’s diplomat, liked and admired by all, if viewed as perhaps “too nice” by some of his ambassadorial colleagues. But even being too nice apparently had its limits. Ambassador Stoessel reportedly threatened to resign if his staff were not also briefed. He filed a formal protest with the Soviets and briefed his staff in short order. Stoessel departed post that September, to be replaced by Ambassador Malcolm Toon in January 1977.

U.S. Embassy Moscow (the old chancery) in 2008.
NVO / Wikimedia

What Was the Purpose of Moscow Signal?

One theory was that the microwaves were being used by the Soviets to activate the numerous listening devices they had emplaced in the building prior to American occupancy. This theory was described in detail by Eric Haseltine in The Spy in Moscow Station (2019), which recounted the efforts of National Security Administration Officer Charles Gandy to get to the bottom of the microwave issue in the late 1970s. His conclusions, which are still highly controversial and were based on a technical survey done at Embassy Moscow in 1978, were that the Soviets were using microwaves (Moscow Unidentified Technical Signals, or MUTS) to activate passive bugs in the walls of the embassy that were much more advanced than the “Thing” (the Theremin device) that had been found in Spaso House.

In addition, Gandy believed that MUTS were being used to read voices off windows by “RF imposition” and could be used to intercept electronic signals and voices reflected off electronic devices in unprotected areas by a technique known as RF flooding. Gandy also pioneered efforts to uncover the bugged IBM Selectric typewriters in Moscow and Leningrad (Project GUNMAN).

There was another leading theory, as well. Many believed that the microwaves were a jamming signal designed to foil our own electronic devices. However, as the Soviets themselves provided this explanation, it was naturally suspect; and the true answer to this question remains in the classified realm.

Embassy Reaction

The worst fear of embassy staffers was that the microwaves, whatever their purpose, might have some as-yet-unknown health effects. This seemed to be borne out over the years by the finding, in the early 1970s, that an unusual number of people were departing post with elevated white blood cell counts. It also came out that, anecdotally at least, there seemed to be a larger number of cancer cases, and especially leukemia, among former embassy staff than would appear to be normal. Also, in the months following Ambassador Stoessel’s briefing, a State Department doctor reported that several members of the embassy staff displayed symptoms that were nonspecific but had been reported frequently in patients chronically exposed to nonionizing radiation. Symptoms included severe headaches, inability to concentrate and fatigue.

In the wake of the revelations about Moscow Signal, many U.S. embassy employees filed lawsuits against the U.S. government.

All in all, many people in Moscow were agitated and offended by what appeared to be efforts to sweep the whole controversy under the rug. Moscow staffers tended to be a little overwrought in any case, due to the unique pressures of work and life in Moscow, and the efforts of the State Department to assuage their concerns were viewed with extreme suspicion. The clincher for many of them was the unusual incidence of illness on the part of American ambassadors stationed in Moscow. In an article in The New Yorker on Dec. 20, 1976 (“A Reporter at Large, Microwaves–II”, Paul Brodeur reported that not only had two recent American ambassadors to Moscow died of cancer (Llewellyn “Tommy” Thompson and Charles “Chip” Bohlen), but then-Ambassador Walter Stoessel was suffering from a severe blood disorder (Ambassador Stoessel eventually died of leukemia in 1986). To most Moscow staffers, it just seemed like too much of a coincidence.

In the wake of the revelations about Moscow Signal, many U.S. embassy employees filed lawsuits against the U.S. government. In response, the State Department funded a study by the Johns Hopkins University School of Hygiene and Public Health, part of the group that had been secretly studying Moscow Signal all along and had already concluded that microwaves were not harmful. The study, released in November 1978, found no convincing evidence that any employees had suffered “adverse health effects as of the time of this analysis.” According to State Department medical consultant Dr. Herbert Pollack, who advocated on behalf of U.S. embassy employees in a Senate subcommittee investigation, every suit was eventually withdrawn, “without a penny being paid.”

This was not the end of the controversy, however, for while the report purportedly “proved” that embassy personnel were not significantly affected by the microwave bombardment, it was also acknowledged that the study was incomplete. In particular, since cancers and other health effects from microwaves often took many years to manifest, follow-up studies and checkups of affected personnel every two to three years were recommended. As far as I have been able to determine, no systematic follow-up was ever done. The State Department had its report, washed its hands of the matter, and moved on. This was despite the fact that the microwaving of the embassy reportedly continued at least until 1988, and most likely well beyond that date. Over the years, thousands of Americans were exposed.

A subsequent reevaluation of the Johns Hopkins study—“The ‘Moscow Signal’ Epidemiological Study, 40 Years On” in the January 2019 edition of Reviews on Environmental Health—has called into question its methodology and conclusions, and some of the criticisms are devastating. In my view, they discredit the study and point to the need for a complete and more comprehensive re-evaluation.

Built in 1913, Spaso House is the residence of the U.S. ambassador to Moscow.
U.S. Embassy Moscow

My Personal Experience

This is where I come in. I had worked for Ambassador Malcolm Toon in Belgrade and had apparently not disgraced myself, so he recruited me to come out as his staff aide in Moscow shortly after he arrived in 1977. It was my first tour of duty there.

For the most part, I was unconcerned about the microwave controversy. The issue had faded a bit into the background before I arrived, and I was much more concerned about the immediate task of learning my job as ambassador’s aide, which was quite a bit more complicated than the tasks I had mastered in Belgrade. At the time, it seemed to me that the microwave issue was taken more seriously by embassy spouses, who were afraid for their children, than by the embassy leadership, who were, in fact, the ones in the crosshairs of whatever the microwaves might be doing. Screens were put up on the chancery windows, which were said to diminish the microwave emanations getting into the embassy; but for me, it was just another part of life in Moscow. Microwaves continued to be beamed at the embassy throughout my tour, but like most people who arrived in Moscow later on, I was either largely unaware of the controversy or put it out of my mind.

Shortly after my tour was over, I found out that my cavalier attitude toward the microwave issue was not at all justified. State’s Office of Medical Services (MED) informed me in late 1979 that my own white cell count was much higher than normal, and advised me to continue to be tested. In 1985 my white cell count got high enough for MED to recommend that I see a hematologist, so I went to a local doctor in San Clemente, Dr. Tsang P. Fong. He did a bone marrow test (the one where they hammer a spike into the pelvic bone, very uncomfortable). The test confirmed that I had chronic lymphocytic leukemia (CLL) stage zero, but that chemotherapy was not advisable since I had no symptoms, and the cure would be worse than the disease.

As the reality of my illness began to set in, I started studying up on the issue. My research on CLL was not encouraging. Most patients progressed slowly to stage four and survived on average only a few years. I determined to fight the disease as best I could by adopting a healthy lifestyle—it’s really all I could do. State MED knew about the CLL diagnosis and downgraded me to a “Class 2” medical clearance, but didn’t stop me from going overseas, mainly because the jobs I was volunteering for often had no takers.

I have often wondered how many others have faced similar unexpected medical issues over the past few decades.

My white cell count stayed stable through the 1980s, although I did notice that there were periods where I would look especially pale or have slightly swollen glands. My visits to Dr. Fong convinced me, however, that I was doing much better than expected. Most other patients I saw were very sick indeed, a pitiable lot. In the 1990s, for reasons no one can really explain, my white cell count began to normalize. By 1999 my CLL was in remission. At my last State Department physical in 2001, my “Class 1” clearance was restored. In more recent times, my CLL has appeared again, but still at a level that does not require chemotherapy.

To this day, I don’t know exactly how I got CLL. In the back of my mind, however, I have always considered Moscow microwaves to be a prime suspect. I had arrived in Moscow in 1977 in perfect health, and I left in 1979 with a high white cell count and was diagnosed six years later with CLL. This came as a shock, as I have no family history of leukemia. It is a puzzle to which there is still no answer.

Concluding Thoughts

I have often wondered how many others have faced similar unexpected medical issues over the past few decades, and whether Moscow Signal was to blame. Many Moscow veterans from the 1960s through the 1980s are already gone, but a substantial number remain. Like the current victims of Havana syndrome, Moscow Signal veterans also deserve definitive answers to the questions that were raised in their time but subsequently ignored.

One thing does give me more general cause for hope: The attitude of the interagency community toward “anomalous health incidents,” whether in the present day or in the deep past, appears to be changing for the better. The community has at last mobilized to help Havana syndrome victims. I also hope that there will be steady progress toward answers to the current questions about the condition’s causes.

Finally, there is one specific question I would like answered: Is there a link between Moscow Signal and Havana syndrome? We may never know for sure. Speaking personally, it would certainly be a lot more positive for the U.S.-Russian relationship if microwaves turned out not to be the cause of Havana syndrome. But either way, we must find the answers to all outstanding questions, past and present, and let the chips fall where they may. Otherwise, we may risk a third generation of victims.

James Schumaker is a retired Foreign Service officer. During his career (1974-2008), he served four times in Moscow, twice in Kyiv and once each in Belgrade, Leningrad, Soviet-occupied Kabul, Minsk, Vladivostok and Yekaterinburg. More detailed source information on Moscow Signal is available on the author’s blog at