"War crimes" are really an invention of the 20th century, in past wars rape, plunder and pillage were the norm. The treatment of non combatants and prisoners, rules of engagement and such only became a concern in the last few generations.
my opinion
War was always considered the greatest of crimes sure codification of law concerning war crimes have been developed in the last century but there are many fine books written ages ago. Rape, burn, plunder and murder are still the only methods of warfare, there has been no diminishment despite the stories we tell each other about our civilized state. Bagram, Gitmo, Abu-Grahab and the hundreds we know nothing about, the rules of engagement remain the same there effect has been magnified by modern tools. Torture is now an official legal tool of the west.
thankyou for listening, I might be wrong, but