USA

The concept of a war crime is peak 21st century delusional thinking. We love to take things that are inherently bad, such as murdering a whole bunch of people from another country, and pretend that if you do it just right then it's totally fine. We give up on a permanent solution in favor of a minor tweak that does a better job of making the people doing bad things feel justified in their actions than it does in reducing harm.

See also: fossil fuel production, wealth inequality, money in politics, gerrymandering, slave labor, etc.