Throughout Afghanistan, one of the world's most unstable territories, several armed groups are conducting a campaign to overthrow the central government in rural areas, mainly in the south, where cultivation of poppies has flourished since the mujahedeen’s war against the Soviets in the 1980s. The Taliban, considered extinct in 2003, are also profiting from poppy cultivation and have teamed up with criminals to expand their trade.
This situation can be depicted as “protracted armed violence between governmental authorities and organized armed groups”, i.e. as an armed conflict. The Afghan government is thus engaged in an armed conflict - which is internal in nature - with the substantial support of the international community, militarily represented in Afghanistan by NATO-led ISAF and the Operation Enduring Freedom (OEF) coalition.
The significant involvement of foreign troops acting independently against insurgents internationalizes the conflict. ISAF and OEF are operating with the consent of Afghanistan, but the Afghan government do not sit at the head of the chain of command. Consent or authorization is not enough to transform international troops deployed in Afghanistan into proxies of the Afghan troops. In legal terms, forces should be under the exclusive direction and control of Afghanistan, and not simply performing the functions entrusted to them by the beneficiary state and authorized by the United Nations.
As the state hosting international troops has no control over the forces of the contributing states, their offensive operations are governed by the law of international armed conflict, namely the (customary, for the U.S.) rules of Additional Protocol I, the Hague and the Geneva Conventions.
The conflict between the authorities of Afghanistan and insurgents, a conflict in which the state is fighting using its own armed forces against organized groups, which control Afghan territory, has been regulated by article 3 common to the Geneva Conventions. Since December 2009, it is covered by Additional Protocol II to the Geneva Conventions, following Afghanistan's accession to the Additional Protocol in June 2009.
Additional Protocol II does not contemplate the category “combatants”. Combatant, a term referring to individuals who retain the right to participate in combat, has a clear meaning and implications only during international armed conflicts. As insurgents do not have a right to participate in combat, they are subject to penal prosecution. Alternatively, Article 6 prescribes that at the end of hostilities the authorities shall endeavour to grant the broadest possible amnesty to persons who have participated in the armed conflict, although it confirms the illicit nature of their involvement.
In respect to international troops, insurgents are “unlawful combatants”, meaning that they are persons taking a direct part in hostilities without being entitled to do so. Nevertheless, they remain civilians. The phrase “unlawful combatant” is purely descriptive. In wartime an individual is either a combatant or a civilian. Tertium non datur. As civilians, insurgents, warlords or Taliban benefit from the same protection of peaceful civilians during hostilities and are only legitimate targets when they participate directly in combat. What direct participation means remains to be clarified. According to majority opinion, the phrase “direct participation” encompasses all civilians “performing the function[s] of combatants.”
Recently, the International Committee of the Red Cross and the Asser Institute hosted a debate on the question of what constituted direct participation in hostilities. The proposed solutions ranged from “effective engagement” using weapons, to the so-called “membership approach”, which relates to those who belong to an armed group that use military force on a regular basis. According to this point of view, belonging to a group directly participating in hostilities is a sufficient criterion for loss of immunity from attack. In another opinion, irregular combatants may be targeted only in flagrante delicto. This last reading of the norm favours the “revolving door” effect, according to which civilians regain the benefit of immunity from attack as soon as they have dropped arms.
A way of negotiating the revolving-door problem has been proposed by the Supreme Court of Israel in the case of Targeted Killing. The Court held that a civilian who has joined a terrorist organization which has become his home, and that in the framework of his role in the organization commits a chain of hostilities, with short periods of rest between them, loses his immunity from attack for such time as he is committing the chain of acts.
A more restrictive view rests on a parallel between direct participation in hostilities and individual self-defence, in the sense that an individual is considered to participate in hostilities if lethal attack may be justified against him as an act of self-defence, even during an armed conflict. This solution is based on the postulation that the “idea of a boundary between law enforcement, limited by human rights law, and military action, limited by the laws of armed conflict, seems ever less tenable.”
According to this approach, person participates in hostilities when using military force or when his/her use of (lethal) force is imminent. A threat is imminent if it is instant and overwhelming, leaving no choice of means or time for deliberation. Adopting such a paradigm allows human rights monitors to make a secure distinction between a lawful killing during an armed conflict and the murder of civilians.
 International Criminal Tribunal for the former-Yugoslavia, Prosecutor v Tädic, Decision on the Defence Motion of Interlocutory Appeal on Jurisdiction, 2 Oct. 1995, App. Ch., IT-94-1-AR72, para. 70.
 ILC, Report of the International Law Commission on the Work of its 42nd Session (1 May – 20 July 1990) UN Doc A/45/10, Commentary to article 6. S.C. Res. 1890 (2009), 8 October, 2009.
 The Additional Protocol will enter into force 6 months after the deposit of the instrument of accession.
 Protocol Additional to the Geneva Conventions of 12 August 1949, and relating to the Protection of Victims of International Armed Conflicts (hereinafter Protocol I), article 43.
 K. Dörmann, The Legal Situation of “Unlawful/unprivileged Combatants, Int. Rev. Red Cross, 46 (2003).
 A. Cassese, Expert Opinion on whether Israel’s Targeted Killings of Palestinian Terrorists Is Consonant with International Humanitarian Law, Public Committee against Torture et al. v. The Government of Israel et al., June 2003, para. 26.
 HCJ 769/02, Public Committee against Torture in Israel et al. v. Government of Israel et al., 13 December 2006HCJ 769/02, para. 31.
 A. Cassese, supra n 6, at 5.
 HCJ 769/02, supra n 7, para. 28.
 HCJ 769/02, supra n 7, para. 39. The Court cited D. Statman, Targeted Killing, Five Theoretical Inquiries in Law 179, 195 (2004).
 D. Kennedy, On Law and War, 113 (2006).