Earlier quoted context omitted.
"Blacks" is a term with very little basis in genetics. What do you think the bioweapon will target? "Jews" is less diverse, but it's not like there's a single "I am Jewish" marker. Just look at https://en.wikipedia.org/wiki/Genetic_studies_on_Jews to see how difficult is it, with overlaps to other populations, and the need to correlate multiple haplogroups. How do you put all that detection machinery into a bioweapon…
> ... Yes, such a weapon will never be very precise. But since no weapon ever is (collateral damage) that doesn't mean it won't be used. > And how do you prevent the bioweapon from mutating that specificity away? You don't. But even that won't stop such a weapon from being used. Every weapon that man kind has been able to envision and create has been used. Not a single exception.
Setting that aside, the hydrogen bomb has not been used as a weapon, only a deterrent.
Same for the neutron bomb (an "enhanced radiation weapon").
And nuclear depth bombs ("All nuclear anti-submarine weapons were withdrawn from service by China, France, Russia, the United Kingdom and the United States in or around 1990.[citation needed] They were replaced by conventional weapons such as the Mk 54 Torpedo that provided ever-increasing accuracy and range as anti-submarine warfare technology improved." says https://en.wikipedia.org/wiki/Nuclear_depth_bomb ).
"The United States Army Biological Warfare Laboratories weaponized anthrax, tularemia, brucellosis, Q-fever and others.[51] ... In 1969, US President Richard Nixon decided to unilaterally terminate the offensive biological weapons program of the US, allowing only scientific research for defensive measures." says https://en.wikipedia.org/wiki/Biological_warfare .
Have all those weaponized organism really been used as a weapon? Not to my knowledge.
These all sound like exceptions.