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Cuba mystery: What theories US investigators are pursuing

WASHINGTON (AP) — There must be an answer.

Whatever is harming U.S. diplomats in Havana, it’s eluded the doctors, scientists and intelligence analysts scouring for answers. Investigators have chased many theories, including a sonic attack, electromagnetic weapon or flawed spying device.

Each explanation seems to fit parts of what’s happened, conflicting with others.

CUBA SONIC SYMPTOMS
Graphic shows symptoms reported by U.S. diplomats in Cuba; 2c x 6 inches; 96.3 mm x 152 mm;

The United States doesn’t even know what to call it. Secretary of State Rex Tillerson used the phrase “health attacks.” The State Department prefers “incidents.”

Either way, suspicion has fallen on Cuba. But investigators also are examining whether a rogue faction of its security services, another country such as Russia, or some combination is to blame, more than a dozen U.S. officials familiar with the investigation told The Associated Press.

Those officials spoke on condition of anonymity because they weren’t authorized to publicly discuss the investigation. The AP also talked to scientists, physicians, acoustics and weapons experts, and others about the theories being pursued.

Perhaps the biggest mystery is why the symptoms, sounds and sensations vary so dramatically from person to person.

Of the 21 medically confirmed U.S. victims, some have permanent hearing loss or concussions, while others suffered nausea, headaches and ear-ringing. Some are struggling with concentration or common word recall, the AP has reported. Some felt vibrations or heard loud sounds mysteriously audible in only parts of rooms , and others heard nothing.

“These are very nonspecific symptoms. That’s why it’s difficult to tell what’s going on,” said Dr. H. Jeffrey Kim, a specialist on ear disorders at MedStar Georgetown University Hospital who isn’t involved with the investigation.

To solve the puzzle, investigators are sorting symptoms into categories, such as auditory and neurological, according to individuals briefed on the probe.

There can be a lag before victims discover or report symptoms, some of which are hard to diagnose. So investigators are charting the timeline of reported incidents to identify “clusters” to help solve the when, where and how of the Havana whodunit.

While Cuba has been surprisingly cooperative , even inviting the FBI to fly down to Havana, it’s not the same as an investigation with the U.S. government in full control.

“You’re on foreign soil,” said David Rubincam, a former FBI agent who served in Moscow. “The quality of the information and evidence you collect is limited to what the host government will allow you to see and hear and touch and do.”

Especially when you don’t even know what you’re looking for.

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SONIC DEVICE

The first signs pointed to a sonic attack. But what kind?

Some victims heard things — signs that the sounds were in the audible spectrum. Loud noise can harm hearing, especially high-decibel sounds that can trigger ear-ringing tinnitus, ruptured ear drums, even permanent hearing loss.

But others heard nothing, and still became ill. So investigators considered inaudible sound: infrasound, too low for humans to hear, and ultrasound, too high.

Infrasound often is experienced as vibration, like standing near a subwoofer. Some victims reported feeling vibrations.

And it’s not impossible that infrasound could explain some of what diplomats thought they heard.

Though infrasound is usually inaudible, some people can detect it if the waves are powerful enough. For example, individuals living near infrasound-generating wind turbines have described pulsating hums that have left them dizzy, nauseous or with interrupted sleep. Such effects have prompted fierce scientific debate.

The balance problems reported in Havana? Possibly explained by infrasound, which may stimulate cells in the ear’s vestibular system that controls balance, scientists say.

But there’s little evidence infrasound can cause lasting damage once the sound stops.

And the pinpointed focus of the sound, reported by some? Infrasound waves travel everywhere, making them difficult to aim with precision.

“There’s no efficient way to focus infrasound to make it into a usable weapon,” said Mario Svirsky, an expert on ear disorders and neuroscience at New York University School of Medicine.

If not infrasound, maybe ultrasound?

At high-intensity, ultrasound can damage human tissue. That’s why doctors use it to destroy uterine fibroids and some tumors.

But ultrasound damage requires close contact between the device and the body. “You cannot sense ultrasound from long distances,” Svirsky said. No victim said they saw a weird contraption nearby.

None of these sound waves seems to explain the concussions. Usually, those follow a blow to the head or proximity to something like a bomb blast.

“I know of no acoustic effect or device that could produce traumatic brain injury or concussion-like symptoms,” said Juergen Altmann, an acoustic weapons expert and physicist at Germany’s Technische Universitaet Dortmund.

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ELECTROMAGNETIC WEAPON

It may sound like Star Wars fantasy, but electromagnetic weapons have been around for years. They generally harm electronics, not humans.

The electromagnetic spectrum includes waves like the ones used by your cellphone, microwave and light bulbs.

And they can be easily pinpointed. Think lasers. Such waves can also travel through walls, so an electromagnetic attack could be plausibly concealed from afar.

There’s precedent. For more than a decade ending in the 1970s, the former Soviet Union bombarded the U.S. Embassy in Moscow with microwaves. The exact purpose was never clear.

What about the sounds people heard?

Microwave pulses — short, intense blasts — can cause people to “hear” clicking sounds. According to a two-decade-old U.S. Air Force patent, the American military has researched whether those blasts could be manipulated to “beam” voices or other sounds to someone’s head.

But when electromagnetic waves cause physical damage, it usually results from body tissue being heated. The diplomats in Cuba haven’t been reporting burning sensations.

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SOMETHING ELSE

The stress and anxiety about the disturbing incidents could be complicating the situation. Diplomats may be taking a closer look at mild symptoms they’d otherwise ignored.

After all, once symptoms emerged, the U.S. Embassy encouraged employees to report anything suspicious. Many of these symptoms can be caused by a lot of different things.

At least one other country, France, tested embassy staffers after an employee reported symptoms. The French then ruled out sonic-induced damage, the AP reported .

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Not knowing what’s causing the crisis in Cuba has made it harder to find the culprit. If there is one at all.

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THE CUBA THEORY

It was only natural that American suspicion started with Cuba.

The attacks happened on Cuban soil. The two countries routinely harassed each other’s diplomats over a half-century of enmity. Despite eased tensions over the past couple of years, distrust lingers.

Diplomats reported incidents in their homes and in hotels. Cuban authorities would know who is staying in each.

But what’s the motive?

When symptoms emerged last November, Cuba was working feverishly with the U.S. to make progress on everything from internet access to immigration rules before President Barack Obama’s term ended. Officials still don’t understand why Havana would at the same time perpetrate attacks that could destroy its new relationship with Washington entirely.

Cuban President Raul Castro’s reaction deepened investigators’ skepticism, according to officials briefed on a rare, face-to-face discussion he had on the matter with America’s top envoy in Havana.

Predictably, Castro denied responsibility. But U.S. officials were surprised that Castro seemed genuinely rattled, and that Cuba offered to let the FBI come investigate.

Then, Canadians got ill. Why them?

The warm, long-standing ties between Cuba and Canada made it seem even less logical that Castro’s government was the culprit.

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THE ROGUES

If not Castro, could elements of Cuba’s vast intelligence apparatus be to blame? Investigators haven’t ruled out that possibility, several U.S. officials said.

It’s no secret that some within Cuba’s government are uneasy about Raul Castro’s opening with Washington.

“It’s entirely possible that hard-line elements acted,” said Michael Parmly, who headed the U.S. mission in Havana until 2008.

But mounting unauthorized attacks, tantamount to aggression against a foreign power, would be a risky act of defiance in a country noted for its strong central control.

Cuba’s surveillance of U.S. diplomats in Havana is intense. The government tracks U.S. diplomats’ movements and conversations.

So at a minimum, if Americans were being attacked, it’s difficult to imagine Cuba’s spies being left in the dark.

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THE OUTSIDERS

Who else would dare?

U.S. investigators have focused on a small group of usual suspects: Russia, Iran, North Korea, China, Venezuela.

Russia, in particular, has harassed American diplomats aggressively in recent years.

Moscow even has a plausible motive: driving a wedge between the communist island and “the West” — nations such as the United States and Canada. Russia also has advanced, hard-to-detect weaponry the much of the world lacks and might not even know about.

None of officials interviewed for this story pointed to any evidence, however, linking Russia to the illnesses. The same goes for the other countries.

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SPYING GONE AWRY?

Maybe no one tried to hurt the Americans at all.

Several U.S. officials have emphasized the possibility the culprit merely surveilled the U.S. diplomats using some new, untested technology that caused unintended harm.

You might think eavesdropping devices simply receive signals. But the world of espionage is full of strange tales.

During the Cold War, the U.S. Embassy in Moscow discovered Russia listening to conversations through a wooden plaque that the American ambassador received as a gift. The plaque had a tiny “microphone” and antenna embedded, but no power source, making it hard to detect even when the room was swept for bugs.

The Russians had developed something novel. They remotely beamed electromagnetic waves to activate the device, which then transmitted sound back via radio frequencies.

Yet if the Cubans or anyone else were equally as innovative, it’s unclear why the incidents would have continued once the United States and Canada complained.

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Associated Press writers Michael Weissenstein in Havana, Ben Fox in Miami, and Matthew Lee, Bradley Klapper and Sadie Gurman in Washington contributed.

EDITOR’S NOTE _ Third in a series of stories.

Pete Buttigieg returns to first-in-the-nation South Carolina with a fresh appeal to Black voters

Orangeburg, South Carolina (CNN) — Pete Buttigieg has been to this small but historic city in South Carolina’s Midlands at least twice before, as an underdog presidential candidate in 2020 and then as the better-known transportation secretary under President Joe Biden in 2023.Now a private citizen eying a second White House bid, Buttigieg returned this weekend with renewed urgency, appealing to Black voters who have newly solidified influence in the 2028 nominating process and whom he failed to win over in his last presidential campaign.Buttigieg told party activists during a morning speech in Florence that Republicans were using redistricting as “the culmination of a generational project to dismantle Black representation.” He held a roundtable with students at a historically Black college where he discussed his idea of reparations for slavery. And during an evening speech to the storied NAACP branch here, he said President Donald Trump’s second term may feel all too familiar to activists who fought for civil rights in Orangeburg in the 1960s.“The mid-2020s does not represent our nation’s first experience with corruption and self-dealing, with bigotry and exclusion, with inequality and injustice, with undemocratic behavior or with political violence,” Buttigieg said, adding that prior struggles played out “not on some distant shore, but in places like Orangeburg.”With a midterm election looming where both parties are campaigning over the cost of living, Buttigieg chastised fellow Democrats whom he said prefer to prioritize economic concerns over tackling more fundamental questions about democracy. He argued that civil rights legends such as Martin Luther King Jr. and Rev. Jesse Jackson have shown that Americans “can — and we must — do both.”His trip to South Carolina, Buttigieg’s first since leaving the Biden administration, marked the beginning of a new phase of political maneuvering ahead of the next presidential election, with Buttigieg making a concerted effort to get in front of Black voters and demonstrating new bonafides from his transportation secretary tenure.It was also the first major visit by a potential 2028 candidate to the state since the Democratic National Committee voted on August 15 to keep it as the location for the first presidential primary in the nation, a nod to the political power of its large Black electorate.Buttigieg brushed off a question about his 2028 plans after his speech in Florence, telling reporters he is “totally focused on 2026.” But there were ample reminders of speculation about his next move on Saturday, including a scattering of homemade signs reading “PETE” and “2028” that sprung up when he took the stage. Surveying the enthusiastic crowd, he observed he should “come here more often.”One fan, 64-year-old retiree Karen Ench, wore a “Pete Buttigieg 2028” shirt to the speech. Contemplating his 2028 ambitions afterward, she said she thought he was “really taking it much more serious” and focusing on areas of improvement from 2020.A 2028 bid would undoubtedly start with higher expectations for the onetime mayor of South Bend, Indiana, compared to his first run.“The Pete Buttigieg of 2020 is not the Pete Buttigieg of 2026,” said Marlon Kimpson, a Black former state senator who backed Biden in the 2020 primary. “He has name recognition, he’s no longer introducing himself. I think people generally like Pete, and that’s a big deal in an open race because he starts out at a plus. But as we look at his economic agenda, just for the average South Carolinian, with emphasis on the African American community … and the political infrastructure he has deployed in our state, there will be questions with respect to those issues.”Buttigieg’s 2020 campaign, despite winning the Iowa caucuses with a much Whiter demographic, came to an end in South Carolina, dogged by his weaknesses with Black voters. After powerful South Carolina Rep. Jim Clyburn endorsed Biden and gave his flagging bid a shot of momentum that ultimately propelled him to the presidency, Buttigieg finished fourth in the Palmetto State and dropped out a day later.Biden received 61% support from Black voters in South Carolina, while Buttigieg got 3%, according to exit polls.Colleen Condon, a Charleston lawyer and longtime party activist who backed Buttigieg in 2020, said that “2020 is so hard to compare against” due to the unique circumstances of Clyburn’s support for Biden. Now, Condon, who is White, said, Democrats are “anxious for someone young and energetic” and noted Buttigieg would bring more experience to the 2028 race.“He has done a lot of work in the last eight years, (including) as secretary of transportation, in showing his ability to work on the federal level,” Condon said.‘What he’s actually done’In interviews across the state on Saturday, Black Democrats agreed Buttigieg’s experience as transportation secretary has distinguished him since he last sought their support. He played a high-profile role in promoting Biden’s bipartisan infrastructure law, visiting communities small and large across the country to announce funding for long-awaited projects.In Florence, Mattie Thomas, a member of the South Carolina Democratic Party executive committee, said she did not know about his time as mayor but now she sees him as “one of our best transportation secretaries.”“I think he’ll fare extremely well this go around because people, they’ve seen what he’s actually done,” Sandra Burgess Glover, a retired educator, said in Orangeburg as Buttigieg mingled with the dinner crowd before his speech.Buttigieg was showered with praise at the dinner for his June 2023 announcement in the city with Clyburn of a $23 million federal grant to better connect Orangeburg’s two HBCUs to downtown. Orangeburg Mayor Michael Butler prompted a standing ovation for Buttigieg when he brought up the project, calling it “a long time coming.”Deloris Frazier, a member of the Orangeburg County Council, embraced Buttigieg as he worked the crowd before the dinner, telling him that she keeps a photo in her home of the two of them from that day in 2023. She told CNN afterward that she’d support Buttigieg for president if he ran, joking that she would take the photo and “just blow it up and make it bigger.”Earlier Saturday, Buttigieg visited one of Orangeburg’s HBCUs, Claflin University, and held an hourlong roundtable with about 20 students. The conversation topics ranged from artificial intelligence to reparations for slavery, which was a litmus test in the 2020 primary.Buttigieg said he still supported legislation to create a commission to study reparations. But he said he learned as transportation secretary that the federal government could take “reparative” steps sooner, pointing to his efforts to combat decades-old urban planning that led to highways cutting across Black neighborhoods.“I have a perspective on that that I didn’t have before when I didn’t have a chance to work on federal policy,” Buttigieg said.Usir Jackson, the president of the Student Government Association, said afterward he found Buttigieg “down to earth” and “authentic.”Buttigieg, who took notes at some points, appeared moved when the roundtable topic turned to young voters feeling disillusioned – and Jackson shared why he still makes sure to vote.“I do it to respect people who came before me,” Jackson said, “so I could vote.”Hurdles remain with Black votersFor all the praise of his record in the Biden administration, some of Buttigieg’s admirers acknowledge he needs it to translate into far more Black voter support than he saw in 2020.While the crowd he spoke to in Orangeburg was overwhelmingly Black, the audience that came to see him earlier in the day in Florence, at the state Democratic Party’s Spratt Issues Conference, was mostly White.State Rep. JA Moore was a crucial Black supporter for Buttigieg in 2020 in South Carolina, backing him after then-California Sen. Kamala Harris dropped out. Moore said in an interview that any potential 2028 candidate needs to focus less on tailoring a message to Black voters and more on developing a “cadence” of regularly reaching out to them where they are.“What we call it is the difference between a ‘come here’ and a ‘been here,’” Moore said. “I think one of the things people missed about Joe Biden – he was a ‘been here’ in the sense that he had been coming to South Carolina for over 40 years.”Some Black Democrats said he may continue to face hurdles in the state as a gay man, an issue that came up in 2020 as he reached out to socially conservative church congregations. “This is the Bible Belt,” Thomas said matter-of-factly.“Sometimes they want to categorize a candidate or individual because of their sexual preferences,” said Brenda Montgomery, a 67-year-old training specialist from Lake City who saw Buttigieg in Florence. “But for me, he is everyone. He represents everyone, and I really like him as a person because he is approachable.”Buttigieg, whose crowd in Florence was dotted with some small rainbow flags, does not go out of his way to talk about his sexual orientation. But on Saturday, he spoke regularly about his two children, who are mixed-race, that he adopted with his husband, Chasten, noting fatherhood is the biggest personal change he has experienced since 2020.It’s a life change that would be put to the test by another grueling presidential campaign, which South Carolina Democrats see as likelier than ever. While he mostly avoided talk of 2028, he said in Florence that he was excited about South Carolina’s first-in-the-nation status and how it would spotlight the state’s diversity.Buttigieg has fielded the 2028 speculation by becoming one of the most prolific endorsers in the midterms, with an eye on supporting Black Democrats and Democrats running in Republican-leaning territory. He kicked off his South Carolina trip on Friday night by headlining a fundraiser in Charleston for Nancy Lacore, a retired Navy officer running for an open House seat in a district that Trump carried by 13 percentage points in 2024.Condon, the Democratic activist who helped host Buttigieg’s fundraiser for LaCore, said it was “extremely early, but I’m very inclined to” support Buttigieg again in 2028 if he runs.Moore said it was too early for endorsements but said he especially likes Buttigieg for at least one reason.Buttigieg “has the ability to learn and adapt,” Moore said. “I find that refreshing and appealing.”The-CNN-Wire™ & © 2026 Cable News Network, Inc., a Warner Bros. Discovery Company. All rights reserved.
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