Despite recent attempts by such influential authors as Steven Pinker, Pieter Spierenburg, or John Mueller to downplay the importance of organized violence in the twentieth century, there is no doubt that this was by far the bloodiest era in human history. No amount of imaginative and arbitrary use of statistics—such as Pinker's pairing of apples and oranges where, for example, human casualties resulting from 1,800 years of Mideast slave trade are treated in the same way as the six years of unprecedented mass slaughter in World War II—can deny this simple fact. Moreover, unlike the premodern world where individuals were generally killed for where they were (i.e., resistance to religious conversion, occupation, enslavement, or territorial loss), in modernity the tendency is to murder people for who they are—their ethnicity, “race,” religion, class, or ideological orientation. In other words, it is no accident that the proliferation of mass murder historically coincides with the expansion of political extremism. In the modern era, and particularly in the twentieth century, ideology has played a much greater role in the mobilization and legitimization of violent extremism.

In this highly erudite book, Manus Midlarsky attempts to explain the origins of twentieth-century extremist social movements and their pathways toward mass murder. Drawing on up-to-date research in social psychology, political theory, history, political science, and philosophy, the author develops an original theory aimed at tackling the emergence of violent political extremism. Since not all belligerent extremist organizations have ended up committing mass-scale slaughter, Midlarsky's focus is on the key social and historical processes that are likely to tip the extremist groups toward indiscriminate violence. In the author's view, a combination of factors, including initial ephemeral gains, contraction of the space of authority, intense emotional experience of humiliation, shame, and anger, as well as heightened awareness of morality and later territorial loss, creates an explosive cocktail that is likely to lead toward the unmitigated killings of huge numbers of individuals.

More specifically, Midlarsky argues that political extremism often emerges in the aftermath of a temporary, but significant, political victory for a particular social movement. However, once this movement finds itself under substantial external threat, fearing that its victory will be reversed (and in some instances this reversal becomes a reality), the tendency is to develop a shared perception of injustice that ultimately leads to common feelings of anger, humiliation, and shame. The direct consequence of this process is the movement's attribution of blame and stereotyping of a group deemed responsible for their expected or actual loss. For Midlarsky, the pathway to extremist violence also entails a substantial degree of “mortality salience”; that is, an increased sense of one's mortality, which stimulates popular preference for, and unquestioned loyalty to, a charismatic leadership. For example, the route to extremist violence of the Tamil Tigers in the late twentieth century is traced back to the decline and eventual disappearance of the Jaffna kingdom in 1619; ephemeral gains in civil service and economy achieved by Tamils under British rule; the loss, humiliation, and anger experienced by independent Sri Lanka's language bill (1956), which made Sinhala the only official language; and another ephemeral gain accomplished by the Liberation Tigers of Tamil Eelam's takeover of Jaffna in 1986, followed by the heightened sense of threat that the Sri Lankan Army would capture Jaffna. The ultimate outcome of all these historical processes and events was the advent of violent extremism, resulting in the devastating actions of the LTTE suicide bombers.

Midlarsky has written an impressive book. His central argument is well articulated, carefully elaborated, and tested on a variety of examples from Nazi Germany, fascist Italy, Stalinist Soviet Union, radical Islamist groups, Sri Lanka, Poland, the Balkans, Japan, and Turkey, among others. The book is also well written and based on comprehensive research.

Nevertheless, as with all well-ordered theoretical models, Midlarsky's theory cannot capture all of the complexity and messiness of social life. Some of the case studies analyzed in the book, such as that of a tiny and politically insignificant British extremist group, Al-Muhajiroun, and Croatian nationalism before World War II, seem highly overstretched to fit this theoretical model. Several key concepts utilized are a bit too vague or undefined (i.e., radicalism, extremism, or democracy). For example, it is not clear what parameters are used to distinguish extreme from the less extreme forms of nationalism.

More importantly, what is missing in Midlarsky's study is an analysis of the sociological processes involved. While the author is good at linking micropsychological research with broader macrohistorical transformations, there is not much attempt to engage with the subtleties of the mezzo-sociological world. This is most pronounced in the author's focus on elite behavior; his treatment of nations, ethnic groups, and societies as homogenous entities; and his lack of engagement with the social mechanisms that underpin ideological transformations. While there is little dispute that all human beings share some universal psychological propensities, the complexities of collective action cannot be captured well by the methods of clinical psychology. Simply put, large-scale collectivites such as nations, ethnic groups, and societies cannot be treated in the same ways as individuals: An individual direct experience of personal humiliation is very different from the collectively learned and externally imposed notion of “collective humiliation” marked by an event that happened a long time in the past. Hence, when writing about “a widespread feeling of humiliation [that] pervades Arab societies” (p. 150) or about “Italian perceptions of injustice” over the 1915 Treaty of London, which promised and then denied to Italy the possession of the Dalmatian coast and Fiume (p. 309), Midlarsky assumes that all “Arabs” and “Italians” shared this feeling of humiliation. However, an engagement with more sociologically grounded analyses, such as those by scholars of nationalism (i.e., Ernest Gellner, Michael Mann, John Breuilly or Rogers Brubaker), would show that in the early twentieth century, most citizens of Italy and the Middle East were illiterate peasants who had little or no comprehension of what a nation is and thus could not develop a coherent sense of collective humiliation.

It is important to distinguish between different social strata and show which groups were influenced by the narratives of “national humiliation” and which remained ignorant. To understand how these processes operate and how collective action is generated, one cannot take pronouncements and speeches of the extremist leaders at face value (p. 168). It is also crucial to look at the internal, societal factors that have shaped popular response to extremist political movements like fascism, Nazism, communism, nationalism, and Islamic radicalism. When tackling the problem of mortality salience, one has to differentiate between an individual's sense of personal mortality and nationalist or religious visions that see nation-states and religions through the prism of collective immortality. By focusing on societies rather than just states, one would avoid a too symmetrical view of complex and messy historical realities that are often less visible from the overly externalized analysis.

To sum up, Midlarsky has produced an excellent, theoretically innovative, and empirically rich study. A more comprehensive engagement with the sociological dynamics involved would have made Origins of Political Extremism even better.