The prohibition on hate speech as a matter of international law is decades old and enshrined in core human rights instruments such as the International Covenant on Civil and Political Rights (ICCPR) and the Convention for the Elimination of Racial Discrimination (CERD). Nonetheless, prohibiting hate speech remains a contentious issue, particularly where it has to be balanced against the protection of free speech. Moreover, the notion that hate speech could constitute an international crime (apart from situations of direct and public incitement to commit genocide) is relatively new. The unsettled nature of international law in this area provides ample analytical fodder for Wibke Timmermann in her new volume Incitement in International Law.

Timmermann provides a comprehensive overview of the state of international law concerning incitement to hatred, by focusing on international human rights law and international criminal law while also incorporating insights from philosophy and social psychology. The book's central premise is that incitement constitutes a significant harm to the ‘human commonwealth’ and should be considered contrary to international law where it is likely to contribute to the persecution of marginalized groups. Although Timmermann's study is wide-ranging, three elements are central to her analysis: the harm of hate speech, the prohibition of incitement to hatred under human rights law, and the potential classification of incitement to hatred as the crime against humanity of persecution.

The danger of hate speech is rooted in its very etymology: it seeks to inculcate hateful attitudes in others. These hateful attitudes give life to ‘us-them’ dichotomies and shrink the moral community. Our circle of obligation becomes increasingly smaller and those placed outside of our circle are, in the best case, not worthy of our empathy, and, in the worst case, a vile threat to be destroyed. In her discussion of the harm of hate speech, Timmermann demonstrates a good grasp of the relevant literature by drawing in her analysis on findings from psychological theorists such as Ervin Staub, James Waller, Gustave Le Bon, and Sigmund Freud, as well as philosophers such as Eric Hoffer and Martin Buber. Building on this literature, Timmerman devises five elements that in her view characterize incitement to hatred and distinguish it from ordinary prejudicial speech: negative stereotyping, characterization of the victim group as an extreme threat, advocacy for an eliminationist solution to this extreme threat, public speech, and the presence of a context furthering the effectiveness of the hate speech.

There is a certain persuasive logic to these criteria. However, her argument that incitement to hatred requires an ‘eliminationist’ component, is overly narrow. This term seems to have been borrowed from Daniel Goldhagen's book Hitler's Willing Executioners, who himself drew from Holocaust literature citing the extermenatorisch (exterminatory) nature of Nazi German anti-Semitic ideology. Timmermann uses the term in a way that encompasses not just the actual killing but also the social death of the victims (i.e. it goes beyond incitement to genocide). In earlier stages hate propaganda focuses less on the destruction of the group and more on its association with negative cognitions such as death, filth, and contamination. Surely, the association with negative cognitions is also a significant social harm worthy of prohibition, as such stereotyping may also contribute to discrimination.

As to Timmermann's argument that hate speech requires a certain context to be persuasive and eventually hazardous, this proposition is certainly incisive, but even in the absence of this context instances of hate speech can contribute to its creation. Thus, there is an acute social harm even absent a pre-existing context of discrimination. Moreover, her argument that this context only involves hate speech originating from a state or state-like structure is problematic. One need only look at ethnic pogroms in India for an example of non-state hate propaganda with deadly effects (although, it must be said, such non-state propaganda still occurs with acquiescence of the state). Elsewhere in the book Timmermann also argues that hate speech is always essentially top-down and instrumental (pp. 19–20). While there is certainly an instrumental element to hate speech, it is overly simplistic to argue that propaganda spreads as a result of criminal masterminds directing malleable subjects. In fact, even political elites are constituted of a mix of ‘true believers’ and entrepreneurs. Indeed, inciters may at once be acting instrumentally, to secure their own power, and prejudicially, out of hatred towards the victimized group. Notions of propaganda as a simple form of emotional contagion or hysteria, as suggested in Freud and Le Bon, are also somewhat unnuanced and do not account for the extensive social psychological literature on the forms, functions, and effects of propaganda which has emerged since Freud. Of course the analysis of propaganda is not the central research component of Timmermann's book.

The author's subsequent discussion of incitement to hatred in international human rights law is both comprehensive and thoughtful. In particular, the discussion of the weighing of the harm of restricted speech, as prohibited by Article 20 of the ICCPR, against freedom of speech under Article 19, is fascinating. She argues that ‘the more extreme the eliminationist measures that are called for and the more widespread and popular the organization which engages in these speech acts, the more restrictive and punitive the measures which are justified to comply with the State's obligations under Article 20(2)’ (p. 124). She discusses this proportionality question through numerous examples from international and regional human rights treaty bodies.

Another of the book's strong points is the discussion of incitement as an international crime. Timmermann critically examines how incitement could be criminalized as the crime against humanity of persecution, as well as how it differs from other forms of criminalized speech such as solicitation and incitement to genocide. One should note that during the drafting process of the Rome Statute there was a debate over whether incitement should be included as a form of liability for crimes other than genocide, but this proposal was rejected on the grounds that it might endanger freedom of expression. For its part, the judicial record on this question seems to be mixed.Footnote ¹ However, Timmermann argues that in cases where hate speech meets the five characteristics identified by her, it should be criminalized as the crime against humanity of persecution.

Timmermann analyses the circumstances through which hate speech can constitute such a crime by situating it within the contextual elements of crimes against humanity and the particular features of hate speech. She begins by emphasizing that crimes against humanity, including persecution, require the presence of a state policy (or state-like policy). This ‘policy element’ was not present in the earlier statutes of the ICTY and the ICTR, but was inserted as an innovation in the Elements of Crimes of the Rome Statute for the International Criminal Court. Timmermann argues that the inclusion of this element is more logical than requiring a widespread or systematic attack on a civilian population. Indeed, the state policy element is what really separates crimes against humanity from other, less systematic forms of violence such as organized crime (although one may wonder why non-state-like entities such as militia groups without ongoing territorial holdings should not be held accountable for the commission of serious international crimes). At any rate, Timmermann's argument that crimes against humanity, including persecution, require a state policy element has interesting implications for the international criminalization of incitement to hatred. She contends that, if hate speech as persecution requires a state policy element, then free speech protections derived from human rights law are not a relevant concern, since such protections only belong to individuals. The state has no right of free speech; in particular, it has an obligation to prevent direct and public incitement to commit genocide.Footnote ²

In addressing the tricky question of whether incitement to hatred can constitute persecution, Timmermann relies on the Bikindi trial judgementFootnote ³ to argue that hate speech, like other potential acts of persecution, need not constitute an elucidated crime in international criminal law. Consequently, Timmermann posits that this question is somewhat irrelevant as ‘to amount to persecution, a crime against humanity, the acts would need to be committed as part of a widespread or systematic attack against a civilian population, which, in all likelihood, would consist of violent acts anyway’ (p. 183). This seems to be a weakening of the proposition that incitement to hatred, like incitement to genocide, is an inchoate crime. If incitement to persecution requires the presence of other acts constituting an attack on a civilian population, then is incitement to persecution really an inchoate crime and is it really criminalized ipso facto? The implications of Timmermann's conjecture is that incitement to persecution, like incitement to genocide, will only exist as a form of ‘complicity incitement’ (more akin to solicitation but with a public element) rather than true inchoate incitement. This is likely more of an evidentiary issue than an issue of legal principle. Yet, if the true harm of incitement to hatred and incitement to genocide is to be addressed then these crimes must be prosecuted as inchoate crimes, before the occurrence of the underlying acts. To wait for the occurrence of genocide or crimes against humanity before prosecuting speech acts erodes the preventive aims of the criminalization of these acts in the first place.

All in all, Timmermann's Incitement in International Law is a substantial contribution to the juridical analysis of incitement to hatred. Arguably, it is the only monograph which treats the subject as a whole. Overall, Timmermann addresses all the key issues in a lucid and thorough manner and writes with clarity and logic. This volume represents a solid foundation for further research into the pressing issue of interdicting and punishing incitement before it leads to catastrophic mass atrocities.