I did not know this; he was a grenade launcher, or manned one, I should say.
I imagine that he launched a grenade, following orders, and later found out that among the victims were children who died agonizingly in flames from his grenade. Not what he was expecting to do in defense of his country, I think.
A country should not ask it's children to roast the children of another country, IMO. The ones who care have trouble dealing with it, for some reason. Must be that lack of patriotism and manliness, hmm?