Actually the convention(s)(there are two, but they are collectively known as 'the geneva convention'), does not offer any rights whatsoever to illegal combatants. That is fact.
There is military code, however, this applies to individuals and not standing orders from the C-in-C. That is, you cannot take it upon yourself to torture but you can be ordered to from high up.
There is also a Clintonian edict that was put into effect in 1996(?) that basically afforded legal combatant rights to illegal combatants(effectively rendering the Geneva convention useless). However, this edict has never been tested and it is the military code that is being used in the present scandal not the Clintonian one.
Go and fight tooth and nail in a combat zone, against insurgents that blend in with the civilian population and who have the undying support of a civilian population that wants nothing more that to see your civilization wiped from the face of the earth. Then you may have an appreciation for why the Geneva convention affords no rights to illegal-combatants. You may even find yourself extracting information from a raghead in a rather unpleasant way.
You can put your high ideas to the test: get a band of people together and start attacks on police in your area. Get caught and see what the police do to you in order to find the rest of your rebels.
In fact, if someone kills a cop then they are dead unless they surrender to a lawyer.
These are just local police, what do you think a military does?
Its called martial law and it is not pretty.
We tie the hands of our military behind their back while most of us are eating at Denny’s.
That will delay your arrival at the truth.
Until we get some chemistry in place that guarantees truth-telling in all circumstances by all people, you and I are better off using trickery, incarceration, sensory deprivation, and food manipulation to gently "coerce" truthful answers from our prisoners, eh?!