What has happened to civilian prisoners during the wars of the past? Do they suddenly become the most privileged members of society (locked safely away, regular food, no work) do are they put to use?
I would expect most would get drafted into regular military units (as long as they were fit for service) seeing as non-voluntary military camps were essentially prisons anyway.
The worst of them (murderers, rapists etc…) would get shanghaied into penal battalions, which were no fun at all. E.g. in Russia they were often used as mine clearing details. Not in the slow and meticulous military engineering sense, mind you : they’d just get told to run across and once the reconnaissance by explosion was over, regular troops would follow.
Not sure what you mean by “no work” — if all else fails, there are always big rocks that need to be made into little rocks.
I recall reading somewhere that when the US entered WWII, the inmates of the SoW prison system petitioned to be allowed to do something in support of the war effort. I believe they ended up making cargo netting (the nets you see soldiers descending to get into landing craft).
My Google-fu is failing me, but I remember reading about the son of an expat worker who was jailed, in Kuwait, for drugs offences. He, along with most of the other inmates, were released as Saddam’s forces crossed the border. He managed to get out of the country (I think he hid in the boot of a car) which was, for him, very fortunate indeed.
In World War II, the Soviets simply massacred their prisoners as the Germans approached.
Appears in “Banged Up Abroad” on the Nat Geo Channel, that particular episode doesn’t appear to be on youtube but he was very lucky to escape from jail and a war zone.