https://ihl-databases.icrc.org/custo...cou_us_rule153The US Soldier’s Manual (1984) tells soldiers:
You must report crimes immediately through your chain of command. If the crime involves your immediate superiors, report to their superior. You may also report violations of the laws of war to the inspector general, provost marshal, chaplain, or judge advocate. In any case, the law requires that you report actual or suspected violations immediately so that evidence will not be misplaced or disappear.
Actually obligated...