After 11 September 2001 the literature on terrorism took a decisive turn. Theories that explained terrorism by suggesting economic factors as causal factors, including underdevelopment, were significantly challenged. The 19 individuals which carried out one of the deadliest attacks in history were not economically deprived and most were well-educated. Support began to gather for religious motivations behind terrorism, and given the events of the post-9/11 world, much of this literature singled out Islam.
Some theories went so far as to say that the degree of severity of terrorist acts varies based on the religious backgrounds of the perpetrators, citing high death tolls in attacks committed by al-Qaeda. Muslim groups, the argument goes, are more likely to kill in greater numbers and this was due to religious ideology. Certainly, there are many problems with these arguments including the failure to account for technological advances, the wide availability of deadly materials and the strategic motivations behind types of attacks. Studies that drew these conclusions focused on cases in the post-9/11 world, neglecting millennia of historical cases that cast doubt on the explanations of terror which single out Islam and Quranic interpretations.
For these reasons and more, the recently released Jewish Terrorism in Israel  by Ami Pedahzur and Arie Perliger, is a timely and important contribution to the study of terrorism and the general discussion of extremism in Israel and globally, both historically and contemporarily.
The book is unique and attractive for a number of reasons. First, the authors, both Israeli scholars, were granted unprecedented access to Israeli documents about Jewish terrorism that allowed for a detailed description of events. Pedahzur and Perliger have been "researching Jewish terrorism for more than ten years, during which [they] have gathered thousands of official documents, mostly court protocols, interviewed 25 former terrorists, politicians and spiritual leaders as well as law enforcement officials, and conducted six comprehensive surveys of communities where terrorist groups originated, which include more than 4,800 respondents" (pg. xiii). 
Second, the authors utilize network analysis to explain why the models of hierarchical, vertical networks and command structures are insufficient in explaining Jewish terror groups and they favor explanations based on socialization and horizontal networks.
Third, Pedahzur and Perliger trace the ideological connections between Jewish terrorists in the modern era, like the Bat Ayin group, which was active in recent years, all the way back to the time of the Hasmonean Family of Jewish zealots who perpetrated attacks against the Roman rulers of Palestine — perhaps the earliest recorded acts of terrorism in human history.
Reading through the book, it becomes evident that this is the most complete and detailed account of Jewish terrorism to date. The accounts of several plots of Jewish terrorists, including a number of attempts at destroying mosques on Jerusalem’s Temple Mount and coordinated attacks on Palestinian mayors, is chilling, and the authors skillfully weave the data they collected to make reading an academic book palatable to the casual reader. One account of a terrorist plot from the book is excerpted below.
Early in March 2002, Shlomo Dvir-Zeliger and Ofer Gamliel began to discuss various targets for such an attack. In the end, the girls’ school in Abu Tor was chosen, as the court verdict stated, "with the intention of causing great suffering by murdering girls going to learn at school."…As the day of the attack approached…they invested a great deal of time in putting together the bomb and other components attached to it. They also conducted preliminary scouting expeditions in Abu Tor to ascertain the optimal location for placing the trailer so the explosion would cause a maximum number of human casualtiesthey set the time so that the booby-trapped trailer would explode during the girls’ assembly at 7:30 in the morning. (pg. 121)
The book discusses a number of different Jewish terror organizations from ancient to modern times. It is an important contribution to the literature on terrorism, particularly at this moment in the development of the field, because it highlights acts of terror perpetrated and ideologically supported by religious and ethnic motivations that are not Islamic. This book should be considered essential reading for anyone interested in terrorism in general and political violence in the state of Israel.
Yet, though this book does make solid contributions, it has weaknesses as well. The most notable weakness revolves around the period of the creation of the state of Israel. Despite the fact that groups like the Irgun (IZL) and the Lehi (LHI) were responsible for the most deadly and infamous acts of Jewish terror in modern history, the authors fail to place these groups under the same scrutiny. To be fair, a discussion of these groups is included in the book, however they are not subject to the same network analysis as Jewish terror groups in more recent times. Further, a number of heinous attacks perpetrated by these groups are not mentioned.
It is important, at this point, to review the authors’ definition of terrorism. Their understanding of terrorism which was applied in the book is a four-part definition (pg. xii): Terrorism involves 1) the use of violence, 2) a political motive that activates the violence, 3) an intention to strike fear into the victims and their community 4) the victims of terrorism are civilians or non-combatants. This definition encompasses most of the elements that the mainstream literature on terrorism accepts.
It is striking then, that a book on Jewish terrorism that adopts such a definition would leave out the massacre at Deir Yassin and other attacks against the Palestinian Arab community. Benny Morris, another Israeli academic, describes the attack at Deir Yassin as follows:
Deir Yassin is remembered not as a military operation, but rather for the atrocities committed by the IZL and LHI troops during and immediately after the drawn out battle: Whole families were riddled with bullets and grenade fragments and buried when houses were blown up on top of them, men women and children were mowed down as they emerged from their houses, individuals were taken aside and shot. At the end of the battle, groups of old men, women and children were trucked through West Jerusalem’s streets as a kind of "victory parade" and then dumped in (Arab) East Jerusalem.
All elements of the definition described by the authors are met, yet Deir Yassin did not make it into the text. In fact, the authors steered away from describing attacks against Palestinians during the period when the IZL and LHI were active. Even though the vast majority of those killed during the Irgun’s reign of terror were Palestinian Arabs and the vast majority of their attacks targeted Palestinians; the authors fail to fairly characterize this reality. Instead they claim that Irgun "activities focused primarily on the struggle against restrictions imposed by the British Mandate authorities on the immigration of Jews to Eretz Israel." (pg. 13) Why they chose to omit these events, in what seems to be systematic fashion, is unclear.
Another curious characterization is in the treatment of two assassinations which appear one after the other in the book (pg. 27-31). Folke Bernadotte and Israel Kastner both fell to the bullets of Jewish terrorists, but the ways in which the assassinations were described, particularly the explanations of the motives, left much to be desired.
Kastner was a Hungarian Jew who became embroiled in scandal in Israel after he was accused of aiding Nazis in the mass murder of European Jewry. The authors argue that the libel lawsuit which Kaster filed to fight the accusations, and ultimately lost, paved the way for his assassination by right-wing fanatic members of the Lehi. Bernadotte was a Swedish diplomat that acted as the first United Nations envoy to the conflict. He was assassinated only one day after finalizing a plan for peace which included the immediate return of Palestinian refugees to their homes. This fact, and the fact that Bernadotte was responsible for saving thousands of Jews from concentration camps only a few years prior, was also omitted in the description of his assassination. In the case of Kastner, the authors chose a narrative that allows the reader to possibly rationalize, if not justify, the assassination from a Jewish perspective. No such narrative was afforded Bernadotte.
Yet the most glaring omission in this time period is not in narrative or in acts of terrorism against Palestinians that were neglected. Rather, the biggest weakness is the failure to characterize many activities of the Haganah as terrorist acts.
Of the Haganah and the Palmach the authors say "despite the determination of these groups the option of engaging in systematic terrorism was not viable" and that they believed that "violence should be exercised in orderly fashion." (pg. 10) While this may, or may not be true, this disqualification of the Haganah as a terrorist group is based on criteria that were not in the definition outlined by the authors in their methodology (see above). In fact, criteria such as selecting an option of "engaging in systematic terrorism" or "practicing chaotic violence" were not mentioned prior to the disqualification of the Haganah and not mentioned after. So why exclude the Haganah?
Certainly several isolated Haganah acts fit the definition of terrorism the authors put forward. The Haganah’s participation in Deir Yassin, and a number of other massacres which targeted civilians and intended to harm or engender fear for political motives, is clear in the historical record. Take for example, the destruction of the village of Beit Masir. The Haganah’s Harel brigade, directed by Yitzhak Rabin, perpetrated the destruction of a village and claimed on 11 May 1948 "we are currently blowing up the houses. We have already blown up 60-70 houses". 
The exclusion of the Haganah is at the very least, grounds to raise serious selection bias questions and at worst a reflection of shoddy scholarship. The author’s could have avoided such criticism by providing a reasonable explanation for the exclusion of Haganah acts, but they failed to do so. To claim that the Haganah did not commit terrorist acts because they were more efficient at it, or orderly while doing so, does not make the act any less terrorizing in nature.
The failures in this book, however, do not outweigh the importance of its contributions to the literature on terrorism in general and Jewish extremism in particular. The shortcomings gravitate to a period in the history which is still taboo for many Israelis to address candidly. Leaving this period aside, Jewish Terrorism in Israel sheds light on a brand of terrorism that much of the world has overlooked, and helps us grapple with the formation of radical ideologies, terrorist groups and the socialization of political violence in communities.
. Jewish Terrorism in Israel (Columbia University Press, 2009)
by Ami Pedahzur and Arie Perliger