Technically, the detainees are prisoners of war --- aligned with a terrorist organization who still considers itself at war with the USA. They can't be tried under US civilian law because they aren't citizens and haven't broken any laws in the USA.
Those who can be tried under military law have been. Those who can't be tried but have renounced their allegiance to a terrorist organization (such as Sabri al-Qurashi) have been released if/when some other country is willing to accept them.
Those who by their own statements maintain they are still enemy combatants aligned against the USA are still being held as prisoners of war.
Please relate how your country treats such individuals in a non-terrorist manner?
For instance, my country is not involved in war crimes like the US is.
One of the problems of becoming a "terrorist" is that no one will negotiate your release. The home countries of many of these individuals don't want them back and refuse to accept them.