Sorry I didnt post the direct one for the above
3rd Geveva convention article 4
http://www.icrc.org/ihl.nsf/7c4d08d9b287a42141256739003e636b/6fef854a3517b75ac125641e004a9e68I said it is the difference between a Lawful combatant and an unlawful combatantant. It determines their legal status
Here is more
The relevance of IHL in the context of terrorism
4. Who is entitled to "prisoner of war" status? What is the consequence of failure to qualify for prisoner of war status?
a. In international armed conflict
As previously mentioned, in international armed conflict, members of the armed forces of the States involved (and associated militias) are lawful combatants. It should be borne in mind that in this type of conflict, there are lawful combatants on two (or more) sides: the armed forces of one State fighting the armed forces of another State.
The four Geneva Conventions apply to situations of international armed conflict. It is the Third Geneva Convention which regulates the protection of lawful combatants upon capture by the enemy. Its procedures for determination of entitlement to prisoner of war status by a "competent tribunal" in case of doubt are mandatory.
Unlawful combatants do not qualify for prisoner of war status. Their situation upon capture by the enemy is covered by the Fourth (Civilian) Geneva Convention if they fulfil the nationality criteria and by the relevant provisions of the Additional Protocol I, if ratified by the detaining power.
This protection is not the same as that afforded to lawful combatants. To the contrary, persons protected by the Fourth Convention and the relevant provisions of Protocol I may be prosecuted under domestic law for directly participating in hostilities. They may be interned for as long as they pose a serious security threat, and, while in detention, may under specific conditions be denied certain privileges under the Fourth Geneva Convention. They may also be prosecuted for war crimes and other crimes and sentenced to terms exceeding the length of the conflict, including the range of penalties provided for under domestic law.
Persons not covered by either the Third or the Fourth Geneva Convention in international armed conflict are entitled to the fundamental guarantees provided for by customary international law (as reflected in Article 75 of Additional Protocol I), as well as by applicable domestic and human rights law. All these legal sources provide for rights of detainees in relation to treatment, conditions and due process of law.
Therefore, contrary to some assertions, the ICRC has never stated that all persons who have taken part in hostilities in an international armed conflict are entitled to prisoner of war status.
b. In non-international armed conflict
In non-international armed conflict combatant status does not exist. Prisoner of war or civilian protected status under the Third and Fourth Geneva Conventions, respectively, do not apply. Members of organized armed groups are entitled to no special status under the laws of non-international armed conflict and may be prosecuted under domestic criminal law if they have taken part in hostilities. However, the international humanitarian law of non-international armed conflict - as reflected in Common Article 3 of the Geneva Conventions, Additional Protocol II to the Geneva Conventions where applicable, and customary international humanitarian law – as well as applicable domestic and international human rights law all provide for rights of detainees in relation to treatment, conditions and due process of law.
Does Protocol I Additional to the Geneva Conventions treat "terrorists" the same as it does soldiers?
One of main achievements of Additional Protocol I concerns limitations on the methods and means of warfare introduced in order to better protect civilians. For example, it unequivocally prohibits acts of terrorism, such as attacks against civilians or civilian objects. The treaty also explicitly prohibits acts or threats of violence the primary purpose of which is to spread terror among the civilian population. Needless to say, persons suspected of such acts are liable for criminal prosecution.
Additional Protocol I does not grant prisoner of war status to persons who unlawfully participate in hostilities. It reserves this status to members of the armed forces of a party to an international armed conflict in the sense of the Protocol. Such armed forces must be organized, be under a command responsible to that party and be subject to an internal disciplinary system that enforces compliance with humanitarian law. Moreover, members of armed forces must distinguish themselves from the civilian population in order to be entitled to prisoner of war status upon capture. While traditionally the wearing of a uniform or of a distinctive sign and the carrying of arms openly was required, States parties to the Protocol agreed that in very exceptional circumstances, such as wars of national liberation, this requirement could be less stringent. The carrying of arms openly would be sufficient as a means of distinction.
The Protocol thus provides recognition and protection only to organizations and individuals who act on behalf of a State or an entity that is a subject of international law. It excludes "private wars", whether conducted by individuals or groups, in the same way that the 1949 Geneva Conventions and the 1907 Hague Regulations concerning the laws and customs of war on land had done. Therefore, "terrorist" groups acting on their own behalf and without the requisite link to a State or similar entity are excluded from prisoner of war protections.
http://www.icrc.org/web/eng/siteeng0.nsf/html/terrorism-ihl-210705