Intelligence experts in the United States have suggested that a mystery illness affecting U.S. government officials around the globe, known as ‘Havana syndrome,’ may be caused by pulsed energy.

Havana syndrome was first recognised in 2016 when diplomats and agents working at the U.S. and Canadian embassies in Cuba’s capital Havana began reporting a range of unusual symptoms that had no apparent cause. Initially, more than 20 cases of the illness were reported among embassy staff and their family members. Some of the symptoms described by people with the syndrome included hearing unpleasant sounds such as ringing and buzzing noises, loss of memory, headaches, dizziness, and nausea.

Diplomatic relations between the United States and Cuba had only been re-established in 2015 following many decades of tensions that began during the Cold War. The emergence of Havana syndrome posed a challenge to relations between the two countries, with the U.S. considering closing down its new embassy, less than two years after it had opened. In the years since Havana syndrome was first identified, some 200 suspected cases of the illness have been reported by U.S. officials working in various parts of the world including Russia, China, Germany, Austria, and Vietnam.

The cause of Havana syndrome has become the subject of huge debate, with a number of theories being put forward to explain such strange symptoms. Some experts believe that Havana syndrome is an entirely psychological phenomenon linked to stress, whereas others suspect the syndrome is the result of weapons being used in targeted attacks by foreign operatives.

In early February, the CIA published an interim report providing details of an investigation into 20 cases of Havana syndrome – including many of the original group of cases that emerged in Cuba. Although the report did not set out any final conclusions it stated that ‘pulsed electromagnetic energy’ emitted from a device was a plausible cause for the symptoms exhibited by those with Havana syndrome. The report highlighted that the illness could not alone be explained by psychological and social factors, and other potential causes such as ionising radiation or biological weapons were largely ruled out. Overseen by a panel of intelligence experts, the assessment is thought to have involved the reviewing of more than 1,000 classified documents as well as interviews with people who had experienced symptoms.

Despite the CIA’s suspicion that targeted pulsed energy had caused Havana syndrome, the mystery behind the illness remains largely unsolved. The U.S. Secretary of State Anthony Blinken, who is responsible for America’s foreign policy, discussed Havana syndrome in a recent interview with MSNBC. He told the network: ‘To date, we don’t know exactly what’s happened and we don’t know exactly who is responsible.’

Further investigations into Havana syndrome are being carried out by other U.S. government departments and organisations, including the FBI, with findings expected to be released in the coming months as part of a more detailed final report.

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