Professor Peter Wallensteen is the Dag Hammarskjöld Professor of Peaceand Conflict Research at Uppsala University, Sweden, and is also ResearchProfessor of Peace Studies at the Joan B. Kroc Institute for International PeaceStudies, University of Notre Dame, USA. He is the director and founder of theUppsala Conflict Data Program (UCDP), which since 1982 has recorded ongoingviolent conflicts and collected information on an expanding range of aspects ofarmed violence, including conflict dynamics and resolution. The UCDP data areone of the most widely-used data sources on global armed conflicts, and itsdefinition of armed conflict is becoming a standard in conflict studies. TheUCDP has made its findings available in an online database at www.ucdp.uu.se

Progressive democratization, the presence of a military superpower and the dream of an international order maintained by an international authority do not enhance the appearance of conventional armed conflicts. However, the discovery of new frailties that can be exploited by aggressors, the proliferation of motives – including ideological motives – for waging war, and the spread of technologies that can be used in new forms of warfare have led to war and armed conflicts breaking out of their classic mould, becoming hybrid and going beyond their previous boundaries. The author argues for an updated polemology which endeavours to explain the mechanisms of these new types of warfare.

Calls have been made in recent years for the legal distinction between international and non-international armed conflicts to be removed. Also as of late, confusion regarding the applicable legal regime has been created by so-called transnational conflicts involving non-state entities. These situations do not fit naturally into the two traditional types of armed conflict recognized by IHL from 1949 onwards. The present article centres on how the legal divide that still exists between international and non-international armed conflict can be explained historically. It aims to further the discussion on whether such a distinction is still relevant, as well as on how certain situations could be classified in the existing typology of IHL.

Although international humanitarian law has as its aim the limitation of the effects of armed conflict, it does not include a full definition of those situations which fall within its material field of application. While it is true that the relevant conventions refer to various types of armed conflict and therefore afford a glimpse of the legal outlines of this multifaceted concept, these instruments do not propose criteria that are precise enough to determine the content of those categories unequivocally. A certain amount of clarity is nonetheless needed. In fact, depending on how the situations are legally defined, the rules that apply vary from one case to the next. By proposing a typology of armed conflicts from the perspective of international humanitarian law, this article seeks to show how the different categories of armed conflict anticipated by that legal regime can be interpreted in the light of recent developments in international legal practice. It also reviews some actual situations whose categorization under existing legal concepts has been debated.

States across the globe are increasingly involved in violent conflicts with non-state groups both within and across borders. This new situation challenges the classic distinction in international humanitarian law between international and non-international armed conflicts. However, the changing face of warfare does not diminish the importance of IHL. The essence of this body of law – to protect civilians and persons hors de combat and to lessen unnecessary harm during armed conflict – remains the same. The applicability of IHL must therefore be determined according to objective criteria and must not be left to the discretion of the warring parties. This article seeks to conceptualize the notion of armed conflict and examines the extent to which the existing body of humanitarian law applies to the new asymmetrical conflicts. It finds that the definition given by the ICTY Appeals Chamber in its Tadić Decision on Jurisdiction, which was taken up by Article 8(2)(f) of the Rome Statute, is a useful starting point for an analysis of the ‘triggering mechanism’ of international humanitarian law in asymmetrical conflicts.

The gradual process of state failure is commonly accompanied by armed violence. Apart from occasional outbreaks, armed violence in fragile states tends to smoulder with relatively low intensity, often over an extended period of time. The actual level of violence may oscillate around the level of violence that is commonly accepted as triggering the application of international humanitarian law (IHL). In addition, because of the specific objectives typically – though not necessarily always – pursued by armed groups in failed state conflict scenarios, cross-border spillover effects are fairly frequent. The qualification of armed violence in such scenarios according to the conflict categories laid down in IHL thus raises some rather specific issues. Moreover, weak states, failing states, and ultimately failed states are increasingly perceived as a key threat to international security. States seem increasingly inclined to assume sporadic order maintenance functions in the place of disabled governments so as to maintain the perceived security threat at a tolerable level. Current efforts to repress acts of piracy off the coast of Somalia are an evident case in point. Since the Security Council, in Resolution 1851, at least implied the possibility of applying IHL in that specific context, the application of this legal regime to sporadic law enforcement operations by third parties also demands further scrutiny.

Modern armed forces are employed in a wide array of operations that range from peacetime riot control to outright international armed conflict. Classifying these various scenarios to determine the applicable international law is rendered difficult by both the lack of clarity inherent in the law and the political factors that tend to enter the decision-making process. The author describes the major challenges of legal classification facing the military leadership, and proposes a solution to ensure that the intended beneficiaries of the law – from soldiers to civilians – do indeed receive its protection.

This article compares the concepts, scopes of application and procedural regimes of war crimes and grave breaches, while considering what role remains for the latter in international criminal law. In addition to their original conception as international obligations to enact and enforce domestic crimes, grave breaches have taken on a new meaning as international crimes, similar to war crimes. Only in few regards does the scope of application of these new grave breaches surpass that of war crimes. The procedural regime of grave breaches differs in theory significantly from that of war crimes, though less so in practice. Although it is too early to discount grave breaches, they are likely to become confined to history.