by Gerhard Werle. The Hague: Asser Press, 2005. 486pp. (Distributed through Cambridge University Press in the USA). Hardcover. £65.00/$ 120.00. ISBN: 9789067041966. Paperback. £ 33,00 / $ 58,00. ISBN: 9789067042024.

Reviewed by Henry (Chip) Carey, Dept. of Political Science, Georgia State University. Email: Polhfc [at]


Gerhard Werle’s treatise on PRINCIPLES OF INTERNATIONAL CRIMINAL LAW remains the best exposition on the subject. Based on an earlier German edition and written in the German style of thorough exposition – with complete introductory bibliography to each section, followed by paragraphs of different type font, based on the degree of specialized knowledge – the book outlines all the historical and legal issues associated with the International Criminal Court (ICC). The focus on the ICC Statute is justified because it, along with the Elements of Crime and procedural rules, developed before and after the July 1998 Rome Statute, “is without question the high point of efforts at codification of general principles of international criminal law” (p.90). The book also examines relevant customary international law derived from case law and treaties like the International Court of Justice statute and the 1949 and 1977 Geneva Conventions. Under the ICC Statute’s Article 21(1), the Court only applies customary law secondarily to the Statute and its elements of crimes. It also examines relevant principles of domestic systems of law, both common and civil law countries, especially from Germany with its own domestic legislation implementing the ICC laws for local prosecution.

Principles of domestic legal systems are particularly stimulating because they could, if accepted by ICC judges, fill in many lacunae and ambiguities in the ICC statute. For example, should standards of recklessness and negligence, accepted in many the common law countries for the mental element of crimes, or necessity defenses, and accepted in civil law countries to absolve a defendant otherwise considered guilty, be deemed relevant to ICC jurisprudence? The former would make convictions easier, and the latter more difficult, but it is unclear whether these principles meet the criterion of a principle fitting into most legal systems, as suggested by the ICC Statute as a source of law. Werle suggests that the Statute is often ambiguous and requires consultation of alternate sources of law identified in the statute as relevant, including customary international law and general principles of law found in domestic legal systems. Given the scholarly influence on judges, arguments posited by authors like Werle can be persuasive. For example, Article 30 of the ICC Statute does not clarify the mental element indicating fault. Werle refers to the Modern Penal Code as a source for those principles, from which he suggests that four levels of this criterion exist: purpose, knowledge, recklessness and negligence. Recklessness includes the traditional [*169] civil law concepts of dolus directus in the first degree (purpose), dolus directus in the second degree (knowledge), and dolus eventualis (recklessness), which the Code uses interchangeably. The initial ruling in the Pre-Trial Chamber I in Jan. 2007 in the Lubanga case upheld this tripartite interpretation. A decision by Pre-Trial Chamber II decision in the Katanga - Ngudjolo Chui Case had not yet been issued at the time of writing. Similarly, Article 31(1) (c) on the necessity defense will be determined by court decisions according to this article in the statute. So far, however, the issue has not arisen.

In a clear, expository style, Werle focuses primarily on the intricate relationships between articles in the ICC Statute, including possible contradictions or amplifications, as well as corresponding reinforcements, expansions or reductions in standards available from these “other sources,” which the ICC statute explicitly permits as supplementary sources of law. The book is organized in six parts: foundations (on a general history of public international criminal law), general principles (on how to apply and interpret the statute in prosecutions), and then followed by the four main crimes in ICC jurisdiction, genocide (Article 6, Part III of the book), crimes against humanity (Article 7, Part IV), war crimes (Article 8, Part V) and aggression (Article 9, Part VI). The latter is a short chapter, since aggression is not yet an indictable crime at the ICC, though that could change as a result of the coming year’s meeting of the ICC Preparatory Commission.

The book has obvious use as a reference, a guide for practicing lawyers, or a classroom text. Each of the six parts is a self-contained treatment of its topic, and worthy of reading as an introduction to any of the six topics. Though published a few years ago, prior to any completed cases at the ICC to date, it remains invaluable as an exposition , of the tensions of interpretation the meaning of the ICC’s core crimes. The only topics missing would be the subsequent decisions of the hybrid tribunals adopted for Cambodia, Sierra Leone, East Timor and elsewhere. However, these cases are arguably not as influential in the development of customary international law bearing on the functioning of the ICC. The book outlines the differing standards that have been applied at the ad hoc tribunals on Yugoslavia and Rwanda, previous draft versions of ICC statutes, and competing interpretations of customary international law. Werle and his colleagues give their interpretations and conclusions, while implicitly acknowledging dissenting opinions. As the ICC begins issuing judgments, such as the recent appellate reversal of the initial ruling that President Bashir of Sudan could not be indicted for genocide, this book will be invaluable in identifying the extent to which the ICC judges followed the logic of textual analysis, customary international law, or competing interpretations of appropriate standards.

The historical analysis reviews the failure to prosecute seriously for German War crimes under the Versailles treaty and the far-reaching jurisprudence and impact of the International Military Tribunal at Nuremberg, as well as Tokyo following World War II. Particularly interesting is the discussion of Control Law Number 10 and the follow-up trials in Germany, which deepened both the [*170] substance of crimes and procedure, both as precedents, as well as models for future courts. The case law on the two International Criminal Tribunals for the former Yugoslavia and Rwanda is mostly integrated into the analysis of the four core crimes in the last four parts of the book. What follows are well argued conclusions about sources and interpretation, universal jurisdiction, enforcement and domestic implementation. Werle clearly sides with those favoring audacious, if careful application of international criminal law in domestic law, regardless of the territorial or nationality basis of jurisdiction, and where not possible, under the auspices of the ICC.

Most of the book focuses on the three crimes currently under ICC jurisdiction. Its strength is in identifying both the historical evolution of standards and legal rules, with which reasonable people could disagree on the interpretations of any of them. Werle generally favors the application of standards which presume a more ambitious role, though not beyond what appears to be the majority views on these subjects. He does not advocate beyond what was intended by the framers. For example, destroying the cultural identify of a protected group does not constitute genocide unless they are accompanied by the types of attacks listed in Article 6. Werle explains how ordinary crimes become crimes under international law under the jurisdiction of the ICC by meeting the contextual element for each alleged crime. This would be an intent to destroy a specified group for genocide, a widespread or systematic attack on a civilian population for crimes against humanity, and the existence of armed conflict for war crimes. The contextual element represents the first hurdle of a complex, four-part process. Each of these contextual elements will doubtless be modified and specified in practice, but the definitions of these terms are not self-evident. Since genocide’s contextual element coincides with both the mental (mens rea) and material (actus reus) elements of the crime, some of its tests are merged together and largely fall on the interpretation of terms of art like ‘intent’ and ‘destroy’, which have been established, according to Werle, as customary international law, based on the ICTY and ICTR and other case law, even though these are not technically legal precedents for the ICC. For crimes against humanity and war crimes, the contextual element comes from the objective conditions in the material elements defined for these two crimes under international law as a widespread or systematic attack against a civilian population and armed conflict respectively. If the contextual circumstances are present, then the two-part test of the material element (as defined respectively in Articles 6 and 8) and the mental element (“with intent and knowledge,” Article 30) elements is undertaken. The mental element for war crimes is less strict than for genocide and crimes against humanity because the standard allows for recklessness and possibly even negligence for willful act (due to the language of Article 8), rather than the “intent and knowledge” of the consequences required for genocide and crimes against humanity. The material element is not interpreted through a general provision, such as the mental element’s Article 30 requirement of intent and knowledge, unless modified elsewhere in the statute. However, the material element must meet the required [*171] conduct (including any specific omissions stated in the Statute) and particular consequences identified in the statute. War Crimes provide for several types of lesser (though serious) consequences. The causality is found for crimes against humanity, in addition to Article 30, for the specific count in Article 7(1) (k) of “other inhumane acts of a similar character intentionally causing great suffering.” Thus, the acts have to be inhumane, be similar to other acts listed, causing suffering and intended to do so. Finally, even if the contextual, material and mental criteria are met, someone may still be exempted from conviction for the crimes under international law. In addition to mental illness and intoxication, arguments about self-defense and duress under Article 31(1) of the Statute may exclude criminal responsibility.

As a result of reading this book, one can anticipate many difficulties in prosecuting ICC crimes. First, many massacres of civilians will not be considered crimes against humanity if they are not part of a widespread or systematic attack against a civilian population. Thus, if a leader used banned chemical weapons against soldiers and did not intend to kill civilians that eventually die, the leader’s lack of specific intent for these consequences would not qualify for the deaths of civilians, only soldiers. The required mental element of mens rea under Article 30 means that there must be intent and knowledge, unless a specific article offers a lower standard, which does not happen for Articles 6 and 7 for genocide and crimes against humanity. Standards of either recklessness or negligence, while sometimes common in some civil or common law systems, might only apply in Article 8, with its standards of willfulness for some war crimes rather than intent. Under the ICC statute, actions taken out of necessity can be used reasonably and proportionately used to exclude responsibility for war crimes. Thus, The ICC may one day judge that banned chemical weapons, as a last resort, could be used against an illegal invasion threatening lives of civilians and their property needed for the survival of a nation. The tests of reasonableness and proportionality can be subjective, judging what a leader thought was the lesser of two evils, rather than what outsiders may have considered the case. The case law is not clear if the leader sincerely decides and miscalculates any disproportionate consequences that naturally arise in the fog of war, if it seemed at the time that it was the last and only resort. Thus, the ICC takes the position of civil code systems, rather than common law, which always criminalizes intentional killing of innocent civilians.

Nor can recklessness or negligence be incorporated into the ICC under customary international law for genocide and crimes against humanity. Article 5(a) of the ICTY statute had a lower threshold for “an intent to kill” or at least “an intent to inflict serious injury in reckless disregard of human life to qualify for a crime against humanity.” The standards for the ICC statute are different: Instead of murder, the term is killing; this there is no standard of recklessness, which would not apply to murder, which is intentional, and often premeditated unlawful killing. The standard of intent is what the defendant intended and knew. If he did not know the chemical weapons were dangerous to [*172] civilians years after the event, he is not guilty of genocide or crimes against humanity. In practice, Saddam Hussein was convicted and executed for genocide for his chemical weapons attack on ethnic Kurds at Halabja, Iraq. Apparently, the Iraqi court concluded that Saddam knew and intended what he was doing since attacks were targeted against civilians. Similarly, if an international humanitarian relief mission were denied by a state trying to protect itself from human rights scrutiny, even if the relief were authorized by the UN Security Council, it would be difficult to prosecute for crimes against humanity. The ICC allows a state the right to disobey the UN Security Council’s legally binding decisions, if the ICC concluded that states which attempt to aid their own civilians cannot be guilty of crimes against humanity in the absence the contextual element of a widespread or systematic attack on a civilian population, as required by Article 7 of the ICC Statute. The effort of the host government to aid its own population would likely be a defense.

Genocide prosecutions will also prove difficult given even more difficult requirements to prove an intent to destroy a racial, religious or ethnic group, as opposed to defeating an insurgency in combat which is located deep within a civilian population, unless civilians and soldiers are murdered under detention. War crimes will be difficult to prosecute unless occurring during armed conflict, and often it must be international armed conflict to qualify. In the same example of an international relief effort, there would be no war crimes if the disaster was natural, rather than human-made (annually, natural disasters kill about five times as many people as war and armed conflict). Such scenarios are not raised by Werle directly, but were clear to this reader because of his careful delimitation of the as-yet undefined lacunae in the labyrinth that exists in this most important international institution. Already, we have the problem that the ICC has only led to indictments of Africans, partly the result of the ease of obtaining evidence of criminal intent and consequences. One can see how loopholes in the ICC involving intent and consequences could absolve the US of liability for past use of chemical weapons, including napalm in Japan, Germany and Vietnam, and arguably against Bosnia and Iraq with depleted uranium. The point is not that the US is guilty or not, because President Bashir might never be convicted, either. What is at stake are legal questions, which Werle suggests in all the remaining ambiguity in the laws. They will have political ramifications which may harm the legitimacy of the court, and thus the future performance of international criminal law’s potential contribution to peace and justice.

© Copyright 2010 by the author, Henry (Chip) Carey.