This work joins a growing number of encyclopedic treatments of the subject. Editor Peter Chalk, senior analyst with the RAND Corporation and author of a wide variety of works on national and international security, has assembled a team of sixty contributors. Nearly half of these are graduate students at Georgetown University. Fourteen are academic faculty, seven are independent scholars or consultants, and the remainder are policy analysts, consultants, or fellows affiliated with RAND and other institutes/think tanks.

The introduction describes seven attributes of modern terrorism, which together define the work’s scope. The encyclopedia specifically excludes state-sponsored terrorism. Chalk states, “this encyclopedia catalogs the most important groups, individuals, and incidents that have been associated with militant violent extremism over the past six decades. Its aim is to offer a comprehensive and easily accessible reference work to inform practitioners, policymakers, academics, students, and interested members of the public” (ix). All entries were “selected in terms of their enduring legacy, threat potential. . .or perceived infamy.” (ix). The work contains approximately four hundred signed entries in alphabetical order. The main section runs 775 pages out of the total page count of 871, averaging out to about two pages per article. The length of each article varies from less than a page to around four pages, and each article concludes with a brief further reading list averaging two to six items. “See also” cross-references to related articles are supplied for most articles. Coverage ranges from the best-known subjects (9/11, Bin Laden, John Walker Lindh, Madrid train bombing) to more obscure topics (the Vail Ski Resort arson ecoterrorism, Corsican nationalist terrorism, and the South Moluccan rights movement). Article coverage is relatively uniform: 9/11 receives three pages of text and six further reading entries, and Osama Bin Laden gets four pages and twelve further readings. Black and white photos are included with some entries.

An alphabetical list of entries appears in both volumes. Volume 2 features a chronology of major events (1946–2011), glossaries, a bibliography, a list of contributors, a categorical list of entries, and a thirty-seven-page index. The category list is of limited utility for subject access as it consists of only four classifications: “Individuals,” “Events,” “Groups and Organizations,” and “Miscellaneous.” That said, the index largely saves the day by providing detailed access to specific people, groups, and events lacking their own entries. Its one major deficiency is spotty and inconsistent geographic access points. A separate geographic index would have enhanced access to the content. The thirty-one-page bibliography contains a wealth of sources, but its arrangement by author or title limits its utility. Some type of subject classification, supplemented with an author/title index, would have rendered it more usable.

The most directly comparable work is probably Combs and Slann’s Encyclopedia of Terrorism (Facts on File, 2007), which, sadly, is already becoming dated. This work also consists of short entries, about 325 in all, and similarly attempts to cover a wide range of topics, including killers like Charles Manson and John Wayne Gacy. Its bibliography is much shorter at six pages, but the chronology, covering 1946–2006, concludes with a useful summary: “U.S. and International Reaction to September 11, 2001, Day by Day” which spans September 11, 2001 to November 26, 2001. Ciment’s World Terrorism: An Encyclopedia of Political Violence from Ancient Times to the Post–9/11 Era (Sharpe Reference, 2011) was reviewed in RUSQ (vol. 52, issue 1, 74–75); as noted there, it places more emphasis on historical context, contrasting with Chalk and Combs/Slann’s focus on modern times. Arrangement of entries within each section by country or region facilitates the geographic access that is missing from the other two titles.

Encyclopedia of Terrorism fulfills its aim of providing a broad, but not deep, compilation of information on modern terrorism in all its manifestations. Of the five audience categories cited in the second paragraph above, however, it is likely to be useful only to students and the public. For these groups, the work provides a helpful summary of each topic with suggested sources for more information. Recommended for public and school libraries that can afford the price; an optional purchase for academic libraries that already have the Combs/Slann or the Ciment titles.