The fact that the trials after World War II were sham trials does not somehow mean that trials of Gitmo inmates today would be sham trials; analogy is not causality.
But it is. Any attempt to make the legal system work in these cases would be even more farcical than the post-WW2 trials because it's all down to he-said she-said in effect, unless they've since confessed to something, which would probably be thrown out anyways if their lawyers are halfway competent. And the stigma of victor's justice will attach anyways regardless, just as it attached to even the few just trials conducted at Nuremburg.
Even in wartime you don't automatically shoot spies just cause you can.
Yes you do. Unless you can turn them. Read a freaking book, watch a movie,
something. This is patently false. You're a Brit for chrissakes, you should know something about this via XX Committee if you have any grounding in the subject at all.
Not to mention it's going to be harder to make a legal case that these are spies given that you have yourself claimed that they don't belong to any enemy nation. At best that puts them in the same category as people who hack into the Pentagon. i.e requiring a civil case in the country they were captured before extradition.
Anyone who is not wearing a uniform or some form of recognizable identification, in time of war, engaged in action against the soldiers of a nation-state, is automatically considered to be engaged in espionage and has no protection or rights. That is literally the way international law works on the subject. A lack of own national affiliation is not even referenced, probably quite deliberately to allow the full range of options to be employed against more anarchistic domestic groups.
This is not to say that rebels cannot gain the protections of the Geneva Conventions. One of the charges laid against many German commanders after WW2 was that they had violated them by executing members of the French Resistance who had taken steps to mark themselves out via the use of black armbands. However I severely doubt that's on the table here.
So your comparison is completely useless.
But let me ask a simply question. Should these people have been shot? Even the ones who were later released cause they weren't guilty?
Has anyone been released on the grounds they weren't guilty? Or simply because they weren't thought to pose a danger?
But in the simplest answer, we should have either shot them all or let them all go. It's been done before and it will be done again using the logic laid out above. Half-measures only serve to make the problem worse. The United States has shot itself in the foot before by falling between two stools of ruthlessness and leniency, most notably over the Native Americans. This is just another case of that.
I would, personally, prefer that most of them be let go. But that does not change the fact that you are speaking nonsense.