[wnoise]

Neither of those examples are biological weapons. Aum Shinrikyo used sarin gas, a chemical weapon, in the Tokyo subway attack. Jonestown used cyanide, also chemical, but this wasn't at all weaponized.

In any case, the argument was based on the umbrella term "weapons of mass destruction".

You're right that as a justification, it falls far too short, even had it been true.