The best shot would be to turn them over to the ICC
https://www.commondreams.org/news/hegseth-no-quarter-interna...
But, even if you dismiss the idea of international standards, this is clearly very bad for US soldiers (and sailors, airmen, etc). I wonder if they see that.
Even if you dismiss the idea of international standards, a no-quarter declaration is against _US law_, specifically subject to the penalty of death with no other lawful penalty defined: https://www.govregs.com/uscode/title18_partI_chapter118_sect....