I think there is a lack of chivarly nowadays.
From now on, wars should be fought be each side selecting a champion, and them pitting him against the opponent in some sort of duel, perhaps to the death. Or perhaps the national leaders should have to fight.
But being serious, rules have always applied in warfare as they can make it much less costly for all sides involved. If competing nations or ideologies can respect each other then rules can make war much less brutal. This isn't a new phenomenon, look at the attempts to ban crossbows in the middle ages, for example.
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