I. Introduction

In the 1980s and 1990s there has been an unprecedented degree of international attention to the application of the laws of war to contemporary conflicts. This body of humanitarian rules has been a major consideration in much international diplomacy, and has had considerable impact in some wars and military occupations. However, as in wars earlier in this century, implementation of the laws of war has been uneven. Basic norms have been violated in wars both international and internal. Horrific events in the former Yugoslavia since 1991, and in Rwanda in 1994, have impelled the United Nations Security Council to establish international tribunals in the hope of thereby restoring the effectiveness of rules after they have been flouted. The many efforts by the UN and other bodies to act against violations have involved a daunting array of problems, many of which had been only dimly foreseen.

Questions about implementation addressed in this study include: What are the formal provisions and mechanisms by which the laws of war are supposed to be implemented, and why have they been relatively little used? In practice, what other mechanisms of implementation have been used? How effective has been the increased involvement of the United Nations Security Council since the early 1980s in addressing violations of the laws of war? What have been the particular problems of implementation in some of the major armed conflicts around the world in the 1980s and 1990s? What has been the role of the International Court of Justice as regards implementation? Why have diplomatic efforts calling for observance of existing rules so often been unsuccessful? Do belligerent reprisals have a continuing place in ensuring observance of rules? Are other uses of force, not specifically designated as reprisals, important as a means of countering violations? What is the place of individual criminal prosecutions, and of demands for reparations from states responsible for major violations? How can the international community respond to the demands for amnesty which inevitably accompany peace negotiations? What conclusions can be drawn about how the question of implementation could be pursued?

States, by becoming parties to the 1949 Geneva Conventions, have undertaken "to respect and to ensure respect " for the main conventions on the laws of war. What exactly does this obligation imply, and how is it to be interpreted in today's circumstances? The difficulty that members of the international community face in attempting to ensure that rules are implemented, and to restore their effectiveness after they have been violated, should not be underestimated. The international system differs from domestic politics precisely in the fact that there is no strong central authority capable of enforcing the full range of rules that states and nonstate bodies are obliged to follow. On the international level, despite the increased role of international organizations including the UN, authority is still decentralized. It follows that international structures, organizations and rules have to be based in large measure on consensus, and rules have to be implemented largely through the states that are the main members of international society. When states (or, as in some recent cases, forces trying to establish a state) do not observe the rules, it is hard to make them change course. This problem is particularly severe so far as implementation of the laws of war is concerned.

A complicating factor in the application of the laws of war is that the majority of wars in the post-1945 world have failed to fall neatly into the category of "international armed conflict" - the only category of war to which the main body of the laws of war is formally and indisputably applicable. Most conflicts have been civil wars, or at least have contained a major element of such war. The application of the laws of war to civil wars raises both a legal and a practical problem. The legal problem is that governments have usually been reluctant to create or sign up to a body of law which would bind their freedom of action so far as dealing with armed rebellion is concerned: thus the treaty-based rules formally applicable in such conflicts have been inadequate, though there is now a tendency at the UN and elsewhere to view a wide range of humanitarian rules as applicable, as the establishment in 1994 of the International Tribunal for Rwanda confirmed. The practical problem is that civil wars are notoriously bitter, for several reasons: each side is likely to deny the legitimacy of the other, training in the laws of war may be limited, the neat distinction between soldier and civilian frequently breaks down and the scope for a compromise settlement of the war is usually slight. Trying to secure even a minimal level of observance of rules is peculiarly difficult in such circumstances.

When a civil war is internationalized, in the sense of involving foreign troops on one or both sides, there is a much stronger argument that the whole body of the laws of war is formally in force, especially as concerns the conduct of the outside forces involved. Even then, however, application may involve practical difficulties arising from the special characteristics of civil wars.

A related problem is how to ensure that the rules themselves are sufficiently realistic that they are capable of being applied by belligerents in the peculiarly difficult circumstances of war, that they reflect a real consensus, and that there is a serious intention to observe them. The progressive development and increasing complexity of the rules, especially in the past two decades, may have gone so far that the laws of war have lost meaningful contact with the thinking and actions of at least some states, armed forces, and non-state entities. Further, the manner in which the law is discussed and advocated may have caused problems. Rules which are not properly incorporated in the training and mentality of fighting forces obviously will not work.

Implementation can assume a variety of forms, of which war crimes trials are only one. The term "implementation" is used here to refer to the many ways in which states generally (including belligerents in an armed conflict) apply, and sometimes fail to apply, the international rules applicable in armed conflict. They can be grouped under three headings:

1. In peacetime: training, education and planning, including within armed forces.

2. In time of occupations and armed conflicts: the codes of conduct, rules, commands and actions of the governments and forces involved; and what one belligerent does, during or after a conflict, in response to another's alleged violations of the rules.

3. The actions of third-party states (i.e. those not directly involved in a conflict), non-governmental bodies, and international organizations, aimed at trying to secure compliance by belligerents, including when belligerents have committed major violations of the rules.

In this study I have generally used the term "laws of war". This refers to those streams of international law (especially the various Hague and Geneva Conventions) specifically intended to apply in armed conflicts. In some eyes the term "laws of war" is old-fashioned. However, it has merits. It accurately reflects the well-established Latin term for the subject of this enquiry, ius in bello; and it is brief and easily understood. It has two modern equivalents, both longer. The term "law applicable in armed conflicts" is unexceptionable, but adds little. "International humanitarian law" (IHL), often with the suffix "applicable in armed conflicts", has become the accepted term in most diplomatic and United Nations frameworks. However, it has the defect that it seems to suggest that humanitarianism (rather than interest or professional standards) is the main foundation on which the law is built, and thus invites a degree of criticism from academics, warriors and others who subscribe to a "realist" view of international relations. However "IHL" also has the merit that it is widely seen as encompassing relevant parts of the international law of human rights. Preference for the term " laws of war " does not imply a down-playing of the significance of human rights provisions, whose merging with the laws of war is one of the most significant developments in this field in recent decades.

In the conflicts of the 1980s and 1990s, the actual practice of belligerents has often fallen far short of what might have been expected granted the important developments in treaty law, the high level of formal adherence to treaties, and the unprecedented involvement of the United Nations (especially the Security Council) in matters relating to implementation of the laws of war. Gross violations of well established rules have occurred in the Iran-Iraq War, in the Iraqi occupation of Kuwait in 1990-91, in the former Yugoslavia since 1991, and in many other conflicts both international and internal. In most cases these violations attracted much diplomatic attention, but no effective response. Those engaging in illegal and inhumane practices could and did exhibit contempt not merely for the laws of war but also for those who sought so ineffectually to uphold them.

The problem of implementation has increasingly come to be seen as the central problem of the laws of war. Sir Frank Berman, Legal Adviser to the UK Foreign and Commonwealth Office, has said:

"It seems to many that the problem is not to discover what the law is, or how to apply it to the particular case, or even whether the existing rule is 'satisfactory' or not, but rather how to secure or compel compliance with the law at all".

A natural response to a pattern of violations of the laws of war is to call for new systems of implementation and enforcement. However, since at least 1949, treaties on the laws of war have included a range of formal provisions on implementation generally, including penal sanctions of various kinds; and there have been numerous efforts, including within a UN framework and also by governmental and non-governmental bodies, to reinforce these mechanisms of enforcement and to develop new ones. Why such provisions and efforts have had relatively little impact is the underlying question which needs to be explored.

If a high level of formal adherence by states to the major treaties were a guarantee of enforcement, there should be little problem. At mid 1995 the four 1949 Geneva Conventions had 185 parties - the same overall total as that of UN members, though the two lists were not quite identical. The two 1977 Additional Protocols had gained a respectable number of parties: Protocol I had 138 states parties, and Protocol II had 128.

Unfortunately, the question of how the laws of war are, or are not, implemented has not been the subject of a vigorous tradition of thought. Lawyers tend to think in terms of enforcement through legal processes after a violation, when implementation may take many other forms. Indeed, its most important aspect is implementation through education and training in well-organized armed forces. Much writing on implementation, including that published in law journals, has been narrowly legal or prescriptive in character. There has too often been a formalistic assumption that the main modes of implementation are, or ought to be, those laid down in the conventions. The problems faced by soldiers and decision-makers in armed conflicts have not been explored in depth. It has been assumed - understandably, but perhaps too easily that the main form of analysis involved is judging the behaviour of belligerents by a legal yardstick, when there is also a case for judging the laws of war by the harsh test of how they operate, or fail to operate, in the circumstances for which they were designed.

Analysis of the question of implementation can benefit from a more descriptive approach, looking systematically at the many difficulties, and opportunities, that have been encountered in applying the laws of war. Such an approach employs the methodologies not only of law but also of history, politics, international relations, and strategic studies. The major single-author work along such lines, Geoffrey Best's examination of whether international humanitarian law has worked well or not since the Second World War, reaches pessimistic conclusions. He draws a picture of a body of law with an impressive and admirable superstructure built on insecure foundations, of which perhaps the shakiest is the central, critical distinction between the soldier and the civilian. The law's impact has been much less than had been hoped. Sometimes, indeed, it has been little more than an instrument of propaganda warfare.

This study is based on six underlying propositions:

1. Difficulties in securing compliance are not unique to the laws of war, but arise also in many aspects both of international law more generally, and of the domestic law of states.

2. Implementation of rules of conduct in war is usually best achieved when parties to a conflict have a political and military culture, and a perception of their own interests, which is broadly favourable to observance. Implementation is therefore largely a matter of proper preparation in peacetime. States, their armed forces, their governments, and their legislatures, are among the most important entities for implementing the laws of war. Securing compliance by states (or non-state entities) after there have been violations of the rules is just one small part of the much broader process of implementation.

3. Punishing transgression of norms is particularly complex in cases in which offences are committed in what is perceived as a public cause, in which large numbers of people are implicated in different ways in the commission of the offences, and in which the state or non-state entity in whose name the offences were committed continues to exist and to protect its own citizens.

4. States which are neutral in a particular conflict, or which do not wish to extend or deepen a limited belligerent role, may be particularly reluctant to take measures to punish war crimes by a belligerent.

5. The actual processes by which compliance with law is induced are by no means the same thing as the formal treaty provisions to that end. Institutions whose role is outlined in the conventions, such as Protecting Powers and the International Fact-finding Commission, have hardly had any role in implementation. In practice, when there are legal procedures, they often assume a different character from that envisaged in the conventions: for example, commissions of inquiry rather than trials. In some extreme cases, it may be only possible to induce compliance with the law by making credible threats of reprisals against an adversary, or by major states showing a willingness to intervene militarily to uphold international standards - courses which manifestly involve numerous risks.

6. The public demand in many countries for more effective implementation of international norms regarding warfare will not go away.