Havana syndrome
In 2017, President Donald Trump blamed Cuba of causing unknown attacks which led to these symptoms. The U.S. lowered the number of staff at their embassy. In 2018, U.S. diplomats in China said they felt sick the same way diplomats in Cuba felt. The US intel services have not yet reached a consensus on a cause of the Havana syndrome, though unnamed sources have expressed suspicions to the press that Russian military intelligence is responsible.