International Rules About Soldiers
The Geneva Conventions and supplementary protocols make a distinction between combatants and civilians.
The two groups must be treated differently by the warring sides and, therefore, combatants must be clearly distinguishable from civilians.
Although this obligation benefits civilians by making it easier for the warring sides to avoid targeting non-combatants, soldiers also benefit because they become immune from prosecution for acts of war.
For example, a civilian who shoots a sholdier may be liable for murder while a soldier who shoots an enemy soldier and is captured may not be punished.
In order for the distinction between combatants and civilians to be clear, combatants must wear uniforms and carry their weapons openly during military operations and during preparation for them.
The exceptions are medical and religious personnel, who are considered non-combatants even though they may wear uniforms. Medical personnel may also carry small arms to use in self-defense if illegally attacked.
The other exception are mercenaries, who are specifically excluded from protections. Mercenaries are defined as soldiers who are not nationals of any of the parties to the conflict and are paid more than the local soldiers.
Combatants who deliberately violate the rules about maintaining a clear separation between combatant and noncombatant groups — and thus endanger the civilian population — are no longer protected by the Geneva Convention.
Combatants who do fall within the guidelines of the Geneva Conventions enjoy the following protections:
Prisoners of war must be treated humanely. Specifically, prisoners must not be subject to torture or to medical or scientific experiments of any kind. They must also be protected against violence, intimidation, insults and public curiosity. The public display of POWs is also prohibited.
When questioned — in the prisoner’s native language — prisoners of war must only give their names, ranks, birth dates and serial numbers. Prisoners who refuse to answer may not be threatened or mistreated.
Prisoners of war must be immediately evacuated away from a combat zone and must not be unnecessarily exposed to danger. They may not be used as human shields.
Finally, and most importantly, prisoners of war may not be punished for the acts they committed during the fighting unless the opposing side would have punished its own soldiers for those acts as well.
International Rules About Civilians
Both the fourth Geneval Convention and the two Additional Protocols extend protections to civilians during war time.
Civilians are not to be subject to attack. This includes direct attacks on civilians and indiscriminate attacks against areas in which civilians are present.
There is to be no destruction of property unless justified by military necessity.
Individuals or groups must not be deported, regardless of motive.
Civilians must not be used as hostages.
Civilians must not be subject to outrages upon personal dignity.
Civilians must not be tortured, raped or enslaved.
Civilians must not be subject to collective punishment and reprisals.
Civilians must not receive differential treatment based on race, religion, nationality, or political allegiance.
Warring parties must not use or develop biological or chemical weapons and must not allow children under 15 to participate in hostilities or to be recruited into the armed forces.