Why might a sanction against the use of chemical or biological weapons be part of the geneva conventions?

The Geneva Conventions operate under the just war doctrine, which attempts to make war morally permissible. The Geneva Conventions work to make war a more humane experience.

Chemical and biological weapons, perhaps more than traditional weapons, produce particularly inhumane results. They often do not kill a person, but instead leave the person badly burned, unable to breathe, or unable to see. These effects are considered to be cruel and unusual acts of punishment and violence.

Explanation:

europe would not recognize the confederacy as an independent nation.