@nprofile1q... ... that and actively being disrespectful of the death of the outgroup.
Examples of mass graves of the enemy abound: we've seen Russians do this to Ukranians, we've seen Israelis do this to Palestinians. We've seen US soldiers do a version of that in Iraq. The disrespect for the enemy runs deep.
In the US, executions may be televised. The French revolution, irrespective of its goals, used public executions as a propaganda tool. Public hangings, stoning, etc. exist in more places...