Another dubious purchase by the Defense Department? A strange little gun rumored to cause Havana syndrome. “Havana syndrome” is a term given to the widely disputed health condition experienced by US and Canadian state department personnel stationed overseas. New reporting by CNN revealed that the Pentagon has spent the past year dissecting a strange device worth millions of dollars for possible links to the illness. According to one of CNN‘s sources, the gadget produces the kind of pulsed radio waves, which some have speculated could be the cause of Havana syndrome.