Why is illegal for CS gas (tear gas) to be used in warfare but countries can use it on their domestic population?

Question

Title.

In: 4

Answer 1

retaliation

If you get gassed by the opposition in a war, you’ll probably respond in kind before you know what the gas is that got thrown at you – so if they launch tear gas at you and you respond with sarine, now everyone is using chemical weapons, and if they launched sarine and you respond with tear gas, you look weak.

civilians tend to not have stockpiles of chemical weapons on hand, so that’s not really a concern in a domestic conflict.