The legalities are probably complicated.
If they are POWs, then the war is over and they need to be released.
If they are war criminals, then they need to be tried for their crimes. We don’t seem to be pursuing that option.
We can’t legitimately hold them forever without charges and trials.
We can only do that to conservative protestors from 01/06.
You’re right. I support trials. The excuse is that trials would expose sources and methods. I doubt this is a grave risk considering their crimes are now two decades old. Another alternative, deport them to countries where they will be prosecuted.