By Laurie R. Blank*
Recent events in eastern Ukraine highlight the challenges of identifying the groups involved. Pro-Russian separatists, militants, pro-Ukrainian “street fighters”, nationalists, terrorists — many terms have been used in media reports. Many such groups wear no identifying uniform and others have deliberately covered or removed insignia that might shed light on their origins or loyalties. This mélange of groups and contradictory information raises numerous questions: who is fighting, for what cause, against whom, and on whose behalf. These issues are central to determining whether the situation is an armed conflict and, if so, whether it is non-international or international. A non-international armed conflict exists when there is protracted armed violence between a state and one or more organized armed groups. In certain circumstances, the involvement of a foreign state in that conflict can transform an otherwise non-international armed conflict into an international armed conflict: if the non-state armed group acts under the overall control of the foreign state, the conflict will be an international armed conflict.
The challenge of identifying who is fighting also highlights how the fundamental principle of distinction operationalizes LOAC’s core purpose: protecting civilians and others hors de combat during conflict. This principle obligates all parties to a conflict to distinguish between those who are fighting and those who are not. Article 48 of Additional Protocol I sets forth the basic rule:
In order to ensure respect for and protection of the civilian population and civilian objects, the Parties to the conflict shall at all times distinguish between the civilian population and combatants and between civilian objects and military objectives and accordingly shall direct their operations only against military objectives.
The obligation to distinguish is customary international law in both international and non-international armed conflicts, as the International Criminal Tribunal for the former Yugoslavia held in the Tadić case.
LOAC’s framework transforms the spirit and purpose of the principle of distinction into concrete obligations and protections, based on individuals’ status and conduct. Combatants, as defined in the Third Geneva Convention, are members of the regular armed forces of a state in international armed conflict. Civilians include all persons who are not combatants or members of an organized armed group (and the latter are often called “fighters”).
Distinction is essential to LOAC implementation and compliance in three main areas: targeting, detention and accountability.
First, combatants are entitled to participate in hostilities and are legitimate targets of attack at all times. Others, such as members of organized groups and civilians directly participating in hostilities, are also legitimate targets — but it can be much harder to identify who they are. All others, such as civilians not directly participating in hostilities, POWs or other detainees, are protected from attack. Operationalizing distinction thus requires information about and an understanding of the different individuals and groups to help determine who is an innocent civilian deserving of protection and who is a hostile actor posing a legitimate threat. Inability or failure to do so means that more civilians will face suffering and harm.
Second, detention determinations and authority depend on the distinction between fighters and civilians, as well as among the many different types of civilians — some who are not involved at all, some who support armed groups, and some who fight with such groups. Members of regular armed forces or organized armed groups engaged in armed conflict can be detained without charge until the end of hostilities. LOAC permits the detention of civilians for imperative reasons of security, but such detention must end when the reason for the detention ends. Unlike detention of combatants or fighters, therefore, which is based on their membership in an opposing force, detention of a civilian must be based on an individualized determination of that individual’s threat to security.
Finally, the identification and categorization of persons and property is essential to the accountability process as well, on two main levels: where an individual can or must be tried and the elements of crimes under LOAC. With regard to the former, combatants can only be tried in the same system provided for the prosecuting state’s own forces, usually a court-martial. In the latter arena, grave breaches of the Geneva Conventions and Additional Protocol I are crimes committed against persons protected by each of the Conventions and/or the Protocol, such as willful killing of prisoners of war or protected persons. Notice, in particular, that grave breaches under Article 85(3) of Additional Protocol I are nearly all violations of distinction, including “making the civilian population or individual civilians the object of attack;” “launching an indiscriminate attack affecting the civilian population or civilian objects . . .;” or “making a person the object of attack in the knowledge that he is hors de combat.”
Eastern Ukraine demonstrates many of the challenges for distinction that contemporary conflicts pose, due to the lack of boundaries between conflict areas and civilian areas, or between those actively participating in hostilities and those who are not. Armed groups multiply at a rapid pace, with little information about who a group supports and what role it plays. More problematically, it is difficult to determine who is part of an organized group and who is protecting a home or neighborhood; who is exploiting chaos for criminal gain; or whether a group of armed individuals is consolidating local authority or fighting on behalf of Ukraine, Russia or some other group. As a result, “the boundaries separating peaceful citizens from terrorists and violent thugs [are] murky” and, in areas where Ukrainian forces are operating, “there is a lot of confusion on the question of whom they’re fighting.”
Needless to say, this confusion as to who is fighting translates directly into enormous challenges for targeting decisions: is anyone a combatant? Who should be considered a member of an organized armed group and which groups are part of the conflict? And which civilians are participating in hostilities?
Detention is equally challenging: when detention decisions rest on the ability to distinguish between and among different groups and individuals, the complexity and uncertainty in eastern Ukraine can make such decisions extremely difficult.
Finally, if any forces in eastern Ukraine are combatants — meaning that 1) the conflict is an international armed conflict and 2) the individuals are members of the regular Russian armed forces or militia belonging to Russia that meet the four-part test in Article 4 of the Third Geneva Convention — then Ukraine would need to prosecute such persons in the same forum it uses to prosecute its own soldiers. In addition, the nature of any LOAC crimes that can be charged depends almost entirely on the ability to distinguish and categorize the victims of such crimes as civilians, fighters, combatants, etc.
Eastern Ukraine’s melting pot of armed groups, unidentified regular armed forces, protesters, and others offers a particularly complex challenge to the principle of distinction — which of the persons who appear to be fighting are actually involved in the conflict and which side, if any, do they support? How should such persons be categorized if they are targeted or captured, or subject to prosecution? For these reasons, the principle of distinction is, as the International Court of Justice proclaimed, one of the “intransgressible principles” of LOAC and helping to ensure its effective implementation even in the face of such challenges is essential.
Laurie R. Blank is a Clinical Professor of Law; Director, International Humanitarian Law Clinic, Emory University School of Law.
 There is a strong argument to be made that an international armed conflict between Russia and Ukraine continues on the basis of the situation in Crimea, irrespective of events in eastern Ukraine.
 Prosecutor v. Tadić, Case No. IT-94-1-A, Judgement, ¶ 162 (Int’l Crim. Trib. for the former Yugoslavia, July 15, 1999).
 Prosecutor v. Tadić, Case No. IT-94-1-T, Decision on Defence Motion for Interlocutory Appeal on Jurisdiction, ¶¶ 110, 27 (Int’l Crim. Trib. for the Former Yugoslavia Oct. 2, 1995) (citing U.N. General Assembly Resolution 2675) (“Bearing in mind the need for measures to ensure the better protection of human rights in armed conflicts of all types, [. . . the General Assembly] Affirms the following basic principles for the protection of civilian populations in armed conflicts, without prejudice to their future elaboration within the framework of progressive development of the international law of armed conflict: . . . 2. in the conduct of military operations during armed conflicts, a distinction must be made at all times between persons actively taking part in the hostilities and civilian populations.”). See also Legality of the Threat and Use of Nuclear Weapons in Armed Conflict, Advisory Opinion, 1996 I.C.J. para 79 (July 8) (distinction is one of the ‘intransgressible principles of international customary law’); JEAN-MARIE HENCKAERTS AND LOUISE DOSWALD-BECK, CUSTOMARY INTERNATIONAL HUMANITARIAN LAW Rule 1 (2005); Abella v. Argentina (La Tablada), Inter-American Commission on Human Rights, Report No. 55/97, Argentina, Doc. 38, 1997, para. 178.