Since September of last year, Washington has recalled the majority of its personnel from its embassy in Havana and at least two more diplomats from its consulate in the Chinese city of Guangzhou. The evacuees reported experiencing “unusual acute auditory or sensory phenomena” and “unusual sounds or piercing noises”. Subsequent tests showed that they suffered from sudden and unexplained loss of hearing as well as from various forms of brain injuries. In April of this year the Canadian embassy evacuated all family members of its personnel stationed in the Cuban capital over similar health concerns. More recently, the US issued a travel warning advising its citizens to stay away from the island and accused Cuba of neglecting to ensure the safety of US diplomatic personnel stationed there.

In early September, Douglas H. Smith, who heads the team of scientists tasked by the US government to examine the matter, said that microwave radiation was almost certainly responsible for the diplomats’ ailments. He added that microwaves were considered “a main suspect” and that his team of scientists was now “increasingly sure” that the diplomats had suffered brain injuries caused by microwave radiation. Now the US news network NBC reports that Russia is viewed as the primary culprit behind the mystery ailments that plagued US diplomats. Reporting on Tuesday the news network cited three unnamed officials in the administration of US President Donald Trump, as well as “congressional aides and others briefed on the investigation”. Specifically, NBC reported that the Russian connection was supported by “evidence from communications intercepts” (signals intelligence or SIGINT), though it did not elaborate on their precise nature. It also said that the ongoing investigation into the purported weapon involves the Federal Bureau of Investigation, the Central Intelligence Agency among other US intelligence and security agencies. Another leading actor in the investigation is the US Air Force, said NBC, stating that experts in its directed energy research program at the Kirtland Air Force Base near Albuquerque, New Mexico, are trying to reverse-engineer the alleged weapons based on the symptoms that they cause.

But NBC noted that the evidence remains relatively inconclusive and is not yet sufficient to allow Washington to openly accuse Moscow of having masterminded the alleged microwave attacks on the US diplomats. The news network said it reached out to the Office of the Director of National Intelligence but received no response. A spokeswoman from the US Department of State said that the investigation into the diplomats’ ailments was ongoing and that the Department had made “no determination of who or what is responsible for the health attacks” on its personnel.