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

Another aspect of the ethics is hard to put in a way that makes logical sense, but I’ll try.

It lowers your opponents ability to defend themselves to an unsatisfactory degree, making them an easy target. To then continue to engage the enemy when they are in such a helpless state that the gas brings could be argued as similar to engaging a disarmed enemy, which is a war crime. That ambiguity is another reason why it is not done in warfare, because it may be more trouble down the line for command than it’s worth.

As for why it is acceptable to use on civilians, this is because unlike in war there is no intention to then engage and destroy the civilians, thus incapacitation is not saddled with the same morally grey baggage.