@cjd

Weapons need to be controllable to win wars, which is why nobody except for Russia and Syria routinely uses chemical weapons - and even that on a small scale.

Nobody uses biological weapons either, probably because they are even more uncontrollable. If you poison your own troops or civilians then you not only suffer losses but actually demoralize your own people.

And because nothing is genetics has sharp boundaries (ethnicity, gender etc) GMO makes a very poor candidate for bioweapon.