system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why are countries more willing to get involved in conflicts of other countries when chemical weapons are involved?

I don't understand why countries say they feel morally obligated to punish a country for use of chemical weapons, but will not not feel as obligated when non-chemical weapons are used. Before countries discovered Syria's use of using chemical weapons Syria was shooting and shelling civilians causing much death and injury. If feels like this is just as bad. Why does it sometimes take chemical weapons for a country to take action?
gpt
The indiscriminate nature of chemical weapons are seen as especially heinous in many parts of the world. With conventional munitions it is at least feasible to prevent civilian casualties. Once the use of chemical weapons is known it is fairly easy to outfit troops with proper protection. The only use for these weapons after the initial attack is for terror and the destruction of unprotected civilian populations.