For more than four years, dozens of American diplomats and intelligence personnel stationed in CubaRussia, China, and even on U.S. soil have reported a range of odd ailments – from fatigue and headaches to impaired hearing, dizziness and memory loss – with no known origin or cause.

But according to a government-commissioned report released by the  National Academies of Sciences over the weekend, the illness, dubbed "Havana Syndrome," is "most likely" the result of direct microwave radiation.

The working theory, established by a committee of 19 experts in medical and related fields, pinpointed "directed, pulsed radio frequency energy" as "the most plausible mechanism" to have triggered the wave of maladies.

While the report did not attribute blame or state that the likely attacks were the work of malicious intent, it said the sicknesses stem from "pulsed" and "directed" frequencies, seemingly emanating from a specific area in the room in a well-honed direction. This indicates that the exposure was not "continuous" or induced by a secondary culprit, such as a microwave or mobile phone.

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Marc Polymeropoulos, a retired CIA operative, told Fox News on Monday that he was a victim of one of these attacks while in a hotel room in Russia in 2017.

Since the episode, Polymeropoulos said he has been suffering from debilitating migraines for the last three years and the constant sense of something being very wrong. 

"I have a terrible headache that never goes away, the loss of long-distance vision, tinnitus – ringing in the ears," he said. 

Polymeropoulos assumes he was probably targeted in Moscow because he was one of the officers in charge of overseeing America’s efforts against the Russian government. 

As for the findings from the report – which only examined those impacted in Cuba and not across the globe – Polymeropoulos said it was a welcome relief after his symptoms were dismissed by senior medical agency personnel.

“A renowned group of scientists telling us we weren’t making this up, that this wasn’t psychosomatic, I can imagine (also brought) others a sense of relief,” he said.

The Academies' analysis did not attribute blame to any foreign power. Still, it did illuminate the decades-long use of the tactic and radio frequency research specifically by Russia – giving more credence to long-held speculation of Moscow being behind the likely sonic attacks.

John Hardie, a Russian foreign policy specialist at the Foundation for Defense of Democracies (FDD), explained that during the Cold War, the Soviet intelligence services "used methods that endangered the health and well-being of American diplomats and intelligence officers, such as beaming concentrated electronic pulses and microwaves to eavesdrop on the U.S. Embassy in Moscow – carcinogenic 'spy dust' used to track U.S. intelligence officers."

Nick Dowling, a defense fellow at the National Defense University as well as a two-time policy adviser for presidential campaigns, concurred that "Russia is one of the most advanced technological adversaries in the world and is more than capable of developing a sonic weapon."

"Russia has been the leader in using new technologies to attack targets in covert and confusing ways. Russia is an active leader in what strategists are calling the gray zone of warfare – attacks in the gray zone between war and peace," he said. "Attacking U.S. diplomats in Cuba and China are likely experimentation with this weapon but also serves the political interests of antagonizing U.S. relations with Cuba and China and creates fear, disruption and distraction among U.S. diplomats and officials."

 And although the bizarre symptoms first surfaced in Cuba around 2016, U.S. investigations at that time found no evidence that the Havana government was behind any targeted assaults of U.S. – and later Canadian – personnel. 

However, since relations were restored in the aftermath of the Soviet Union's collapse, there has been a longstanding rule that Russian and U.S. intelligence services do not physically harm each other's officers – if it can be avoided.

"(But) generally the idea is just to break the rules of the game, which normally say rival intel services don't cause physical harm," said Matthew Schmidt, an associate professor of national security at the University of New Haven. "This kind of thing meets the letter of that, it doesn't technically get physical, but it breaks the norm of behavior because it seems to cause pretty severe harm. That destabilizes the game. People are worried, people don't perform as well because they're sick, or they're worried about being hurt and taking precautions against it, which may make them less effective."

FILE - In this April 17, 2018 file photo, a man walks beside Canada's embassy in Havana, Cuba. Canada announced Wednesday, Jan. 30, 2019, it is removing up to half of the Canadians at its embassy in Cuba after another diplomat was found to have fallen mysteriously ill. Canada has confirmed 14 cases of mysterious health problems since early 2017. (AP Photo/Desmond Boylan, File)

FILE - In this April 17, 2018 file photo, a man walks beside Canada's embassy in Havana, Cuba. Canada announced Wednesday, Jan. 30, 2019, it is removing up to half of the Canadians at its embassy in Cuba after another diplomat was found to have fallen mysteriously ill. Canada has confirmed 14 cases of mysterious health problems since early 2017. (AP Photo/Desmond Boylan, File)

The Russian Embassy told Fox News that the "insinuation of Moscow's involvement is "absolutely absurd and bizarre" – but experts are quick to point to a sobering history. 

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Complicating the U.S. government probe is the vast array of differing prognostics and experiences. Some reports have pointed to individuals in either homes or hotels hearing high-pitched tones or jarring thuds from one direction or all around. Some endure a kind of tremoring or a wind-like pressure; some hear nothing at all.

While generally not deemed life-threatening but certainly damaging and injurious, the alleged attacks would be borne out of a desire to drive a wedge between the U.S. and other countries and "mark up the cost" for a diplomat and their family serving American interests.

Nonetheless, the report – which was sent to the U.S. State Department in August for review and has since been the subject of criticism for not being released sooner – recommends that the U.S. government put protocols in place to immediately open a probe should such incidents occur. 

Furthermore, several former and current government officials are pushing for further action to get to the root of what has happened – and could still be happening. It remains unclear just how many Americans have been impacted. However, around 60 are said to have been treated by experts at the Center for Brain Injury and Repair at the University of Pennsylvania. 

"There are a number of Americans who have fallen ill now, and we need to know why and who is behind it," Daniel Hoffman, a former CIA Moscow station chief, who retired in early 2017 just before the strange illnesses began, told Fox News. "This is something worthy of a congressional hearing."

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Polymeropoulos agreed that this needs to be a bipartisan issue, and understanding who is culpable is a pivotal mystery that intelligence agencies will need to solve. However, he stressed that in the meantime, there should also be a bipartisan push to ensure that victims – people who serve the United States in diplomatic and intel capacities as well as their families – receive immediate medical help for their injuries.

Polymeropoulos said his move to go public has resulted in the CIA submitting the necessary paperwork and him being accepted into the Walter Reed National Military Medical Center, where he will begin treatment for traumatic brain injury (TBI) in late January.

“This shouldn’t be one-sided, those affected need to be getting the right treatment,” he added. “No one should be held prisoner, waiting for the outcome of (a full) investigation.”