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

Question

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In: 4

Answer 1

There is basically no military utility to tear gas. The countermeasures are easy enough for any functioning government to come up with, and even if it does work it’s still possible to function under its effect. So in the vast majority of military situations you’d be better served by just chucking a bunch of high explosives at the problem. On the other hand it wouldn’t be unreasonable for a CS gas attack to be reported as “chemical weapons” which could result in a retaliatory escalation, which would be really bad.