The Second World War was a turning point in how we see war crimes. Until then, dreadful things happened in war, and were somewhat seen as a side effect.
The English in the Hundred Years War in France perfected what they called a chevauchée or a horse charge. It meant the army passed through a broad swathe of the countryside decimating it, burning the crops and generally laying waste. The people affected were the ordinary people and ironically even the attackers suffered. They were burning their own food stores too.
The thinking behind it went like this; Edward III was fighting to become the King of France as well as England. The chevauchées were supposed to prove to the French that their king could not protect them and they would be better off with Edward as their king. There is at least some logic there even if we can blow holes as large as cannon fire through it.
Throughout history, we can point to events where massacres, ethnic cleansing, ill-treatment of troops has taken place, but the perpetrators were not called to account. If they were on the winning side they might have been applauded and rewarded. If they lost they were probably executed.
The Second World War
There was a difference in attitude after 1945, with two factors being key in this change and the obvious one being the Holocaust. The other was seen at the time as being a parallel horror, which was the treatment of civilians and enlisted soldiers by the Japanese in the far east.
More crimes than Genocide
The Geneva Convention took the first step in codifying what constitutes a war crime and although genocide is on the list, and is possibly the most prosecuted category it is not the only one.
There are a series of crimes against peace. Technically planning a war or waging a war in contravention of international law constitutes a war crime. Leading a war of aggression is high on the list of crimes against peace.
The next segment is categorized as war crimes. These include unjustified devastation such as the wanton destruction of cities and towns, the killing of hostages or the ill-treatment of a civilian population especially into slave labor.
The biggest segment is crimes against humanity. Interestingly a crime against humanity is still a crime, even if it not a crime in the country where it is perpetrated. Enslaving a population is a no-no even if the country concerned does not outlaw it. Crimes against humanity include murder, rape and deportation.
The value of war crimes
History is usually written by the winners and they are unlikely to prosecute the soldiers who gave them a win however horrific their actions. Because of that prosecuting war crimes can be viewed as a revenge action. In fact, war crimes prosecution allows for the people of the world to stand together and decry a crime. It is not an act of revenge it is a statement of beliefs.