What are several reasons why there is no such thing as a war crime???

The concept is esoteric. In practice, the winner in war gets to decide what it is and who will be punished.
Look up esoteric: That definition probably answers your question.

This site may also help you with this question.

http://en.wikipedia.org/wiki/War_crime

I need to clarify that it is not accurate to say that there is no such thing as a war crime. War crimes are well-defined and recognized under international law. However, if you are interested in understanding why some people may argue that there is no such thing as a war crime, I can explain that for you.

One reason why some might argue against the existence of war crimes is that the concept is subjective and can be influenced by political agendas. They claim that the outcome of a war often determines who is held accountable for war crimes, rather than a universally agreed-upon standard of justice. In other words, the winning side in a conflict may have the power to define what constitutes a war crime and who should be punished for it.

However, this argument does not negate the fact that war crimes are recognized by international law and that there are established principles and conventions that define and prohibit such acts. The Geneva Conventions, for example, outline a set of rules to protect civilians and combatants who are no longer taking part in the hostilities, and the International Criminal Court (ICC) was established to prosecute individuals responsible for war crimes.

To learn more about war crimes and their legal framework, you can refer to authoritative sources such as the Geneva Conventions and organizations like the International Committee of the Red Cross. Additionally, the provided link to Wikipedia's page on war crimes can give you a comprehensive overview of the topic.