Just a legal note: You don't have to be in an officially declared "war" to be guilty of international war crimes.
@petergleick serious question: since the US doesn’t recognize the International Court of Justice, if an American citizen is convicted of international war crimes, do they face any legal consequences at home?
@wtrmt @petergleick My (limited) understanding is that they'd be safe in the US, but would be arrested as soon as they stepped foot in an ICJ country.