Соответствующая норма
Japan
Practice Relating to Rule 146. Reprisals against Protected Persons
Section A. Captured combatants and prisoners of war
Japan’s Law concerning the Treatment of Prisoners of War and Other Detainees in Armed Attack Situations (2004) states: “No person shall expose any adverse distinction on prisoners of war … in revenge for armed attack.” 
Japan, Law concerning the Treatment of Prisoners of War and Other Detainees in Armed Attack Situations, 2004, Article 2(3).