Re: Pertly off the subject....
Atomic weapons are too powerful, and leave lots of radioactive dust floating around that can't be neatly confined to the battlefield. Worse, they invite retaliation in kind which could lead to wiping out the countries involved. It's simply not worth the risk of using these, frankly and easier to agree not to use them, but have a bunch that could be used if other people don't keep to the gentlemans agreement.
Biological weapons could conceivably wipe out the entire planets population. Everybody can agree that this is a bit nuts and well worth avoiding.
It was well established during WW1 that chemical weapons are not a worthwhile war winning weapon even in the most ideal circumstances (on a static battlefield like a trench) and yet do float off in directions unexpected and kill civilians who were not intended to be the targets and can contaminate wide areas which costs megabucks to decontaminate. Again, not worth it.
Whereas bullets and explosive shells are at least nominally aimed at the person they are intended to hit, and have little long term effect on a wider area.
There is little morality to politics, only practicality.
Biting the hand that feeds IT
