Report Points to Microwave ‘Attack’ as Likely Source of Mystery Illnesses That Hit Diplomats and Spies

But since 2018, the U.S. government has declined to speculate publicly on the cases, and some scientists have promoted alternate theories, like a kind of psychological illness that spread in the stressful environment of foreign missions.

Amid the controversy and confusion, some of the afflicted officers have complained that the United States has failed to support them. In several cases, the government initially refused to grant leave and provide the necessary medical care for officers who said they were affected, the officers said. And with the government silent on the possibility of a foreign attack, many of the victims were left feeling that the public believed they had made it all up.

Several of the victims have accused Secretary of State Mike Pompeo and other Trump administration officials of downplaying the issue in an attempt to avoid disrupting international ties. They now ask how President-elect Joseph R. Biden Jr. and his nominee for secretary of state, Antony J. Blinken, will respond, especially given the new scientific findings.

The State Department gave the report to some congressional officials and others on Thursday and Friday and told them not to share it, after lawmakers had pressured the agency for months to release the report. The Times and NBC News separately obtained the report on Friday, and NBC earlier reported the findings.

”We are pleased this report is now out and can add to the data and analyses that may help us come to an eventual conclusion as to what transpired,” the State Department said in a statement on Saturday.

The department also said that “each possible cause remains speculative” and that various factors, including the committee’s lack of access to some information because of potential security concerns, “limit the scope of the report,” though “they do not lessen its value.”

For the Trump administration, acknowledging that the incidents were the result of a foreign attack could have necessitated evacuating American missions in China, disrupting an important economic relationship. The administration did take a harder approach in Cuba, which aligned with its larger goal of reversing President Barack Obama’s diplomatic opening with Havana.