The unexplained death of a researcher at a Russian anti-plague institute has one former senior U.S. arms official warning it could be 'far worse' than the bacteria that caused the Black Death.Marshall Billingslea, who served as President Donald Trump's special presidential envoy for arms control, said a top Soviet bioweapons defector told him decades ago about secret work on antibiotic-resistant plague at the same facility where the recent plague-related death occurred."This may not be just 'the plague.' It may be far worse," Billingslea wrote on X.He spent much of the 1990s working on prolife...