Already in life, ʿAbdallah ʿAzzam was a legend: an ascetic “cleric with balls” (p. 500) whose words and actions aligned and who “spoke truth to power” (p. 480). No wonder that his untimely death in a bomb blast in Peshawar in 1989 (aka “the biggest murder mystery in the history of jihadism” [p. 436]) only added even more hagiographic layers. Since then, ʿAzzam has been turned into an icon of jihadi “pop culture” with a “brand value and level of recognizability comparable to that of Che Guevara on the political left” (p. 466). Thomas Hegghammer, however, is far from star-struck. The Caravan is a careful, impressive, and comprehensive work that drills deep into ʿAzzam's biography. This pioneering book delineates how he became the founder of the so-called Services Bureau (Maktab al-Khidamāt) who through this initiative greatly facilitated the travel of Arab foreign fighters to Pakistan and (sometimes) onward to join the jihad in Afghanistan. Six out of eighteen chapters deal with ʿAzzam's early life in the West Bank, his contacts with the Muslim Brotherhood and the Palestinian Fedayeen movement, and his intellectual formation in Damascus and at al-Azhar, where he completed a doctorate in Islamic legal theory (p. 76). By 1977, the refugee of the 1967 war seemed to have made it in Jordan: ʿAzzam had a large family and a house, was a charismatic and admired university teacher (pp. 80–87) and a senior figure in the Brotherhood who traveled internationally (p. 97). Yet, bitter internal disagreements put his career in disarray and led to his expulsion from Jordan. In the fall of 1980, ʿAzzam found himself in Saudi Arabia, broke and somewhat adrift. His life took a new direction when he was able to climb on the Saudi-sponsored “pan-Islamic” bandwagon, which according to Hegghammer had been accelerating from the 1960s due to “a cluster of religious institutions in Western Saudi Arabia,” such as the Muslim World League. ʿAzzam benefitted from an exchange program between King ʿAbd al-ʿAziz University, the Saudi institution where he was teaching at the time, and the newly established Islamic University in Islamabad, Pakistan (pp. 106–8). His new home in Pakistan's capital brought ʿAzzam much closer to where the jihadi action was. From 1982, ʿAzzam's most productive period as writer, recruiter, and ideologue began, first as a part-time jihadi who only visited Peshawar on the weekends, then full-time starting in 1986. Until his death, he wrote several jihadi classics, such as Signs of the Merciful in the Afghan Jihad (1983) and Join the Caravan (1987). Palestine and the “liberation of Jerusalem” remained on ʿAzzam's mind throughout his life. With the battlefield against Israel inaccessible due to neighboring Arab states preventing fighters “from even getting within striking distance,” Afghanistan had become the ultimate opportunity for boosting Muslim morale and establishing an exemplary Islamic state (p. 25–26).

In narrating this fascinating and untold story, Hegghammer draws on a wide range of interviews and primary Arabic sources to dispel popular falsehoods, such as that the United States trained the Afghan Arabs (pp. 182–4), that the Saudi government helped to create al-Qaʿida (p. 416), and that the Arab foreign fighters made a significant military difference in Afghanistan (p. 365). He emphasizes that until 1984 no systematic recruitment scheme for foreign fighters was in place (p. 166). The Afghan Mujahidin made it clear that they needed money, not Arab volunteers. The Services Bureau was thus an organization with a broad portfolio which covered, for instance, schools, logistics into Afghanistan, and aid (pp. 217–238). When significantly more Arabs arrived later (up to 7,000 until 1989 in Hegghammer's estimate), the Bureau struggled to offer them actual weapons training. This was one of the primary reasons why Usama Bin Laden tried to build his own training facilities, which eventually led to the establishment of al-Qaʿida (pp. 331–38). What emerges from Hegghammer's meticulous and well-sourced account is that ʿAzzam was neither an effective military man nor a particularly talented manager. He was, however, a public relations genius. The Arabic al-Jihad magazine, published by the Bureau, was widely read and distributed on a global scale. ʿAzzam also had a major impact on jihadi thought by advancing the effective argument that “jihad is indeed for the defence of territory, but governments have no say in who should participate” (p. 302). As Hegghammer shows, he was a rather inclusive and conflict-averse figure who denounced factionalism and focused on shared threats against the Muslim community (umma). His emotional speeches lauded the virtues of the “homo jihadicus” lifestyle (pp. 291–94) while remaining unspecific on many important details. This vagueness partly explains the broad and unique appeal ʿAzzam still enjoys “across the entire spectrum of militant Islamist groups” (p. 468). At the same time, this hands-off approach came with a steep price: Hegghammer argues that ʿAzzam's failure to put into place any governance structures for his advocated “privatization” of jihad opened “a Pandora's box of militancy that could not be controlled, precisely because it was reared on rejection of authority” (p. 306).

One of Hegghammer's most important arguments is that the mentioned “pan-Islamist movement,” tacitly supported by the Saudis, provides the “missing link between the inward-looking forms of Islamism of the 1950s and 1960s and the outward-oriented ones of the 1980s and 1990s” (p. 496–97). If Arab Islamists had not been excluded from local politics, if ʿAzzam had not enticed so many to come to Afghanistan, this “most transnational rebel movement in modern history” would not have developed a life of its own and gone global (p. 2). In this discussion, the author brilliantly demonstrates the extent of ʿAzzam's influence. Yet, given how much he remained a religious scholar at heart until the end, ʿAzzam's ideas and oeuvre play a rather subordinated role in the book overall. Relevant chapters provide more of a brief summary than a comparative analysis of, say, ʿAzzam's “geopolitics” (p. 141). Additionally, there seem to be two silences in particular that warrant more investigation. For one, the example of Iran and Shiʿi ideological input lingers in the background but is seldomly explored in more depth by Hegghammer (pp. 99–100, p. 315, pp. 344–45). Second, the Arabs in the author's narrative appear to have virtually no interaction with Pakistani Islamists, even though, for instance, the Pakistani Jamaat-e-Islami sent substantially more volunteers inside Afghanistan (p. 203) and covered the war extensively in its Urdu publications.

Since Hegghammer is forced to cut through a great deal of unreliable information and mythmaking, he occasionally gets carried away with trying to set the story really straight. One example is when he criticizes existing scholarship for misinterpreting documents and claiming that al-Qaʿida was founded in August 1988 when this must have happened “any time between August 1987 and July 1988” (pp. 353–54). However, this does not mean that the book is only recommended for those with a deep fascination for the minutiae of modern jihadism. Quite the contrary: Hegghammer tells a gripping, authoritative story about foreign fighters, their motivations, and their conflicts which succeeds in getting as close to his male (and occasional female) protagonists as historically possible.