Laurence also focuses on the Sunni experience in several European states with significant Muslim populations—namely, Germany, France, Britain, Italy, and the Netherlands. On the other hand, he did not examine to any degree of depth the Muslim experience in other European countries with significant Muslim populations. Belgium and Sweden, for example, have a higher percentage of Muslims than do several of the European countries that he examines in depth. In fact, on a percentage basis, both have roughly three times more Muslims than does Italy. Even in absolute terms, both countries have roughly as many Muslim residents or citizens as does the Netherlands. Laurence does not explain why he chose some European countries and excluded others.

As for the four Muslim states that were the author’s primary focus, even when taken together they hardly constitute the majority of Sunni Muslims. The three North African states—Morocco, Tunisia, and Algeria—were formerly under French rule. Algeria was actually part of Metropolitan France. All three remain Francophone. With the possible exception of Algeria, they have long been considered among the more “moderate” of Muslim states. In that regard, they have differed sharply from what were once the “rejectionist” Arab states such as Syria, Libya, and Yemen, all of which are currently going through various stages of murderous civil war.

One wonders why Laurence did not pay more attention to the Indonesian Muslim experience. Indonesia is, after all, the world’s most populous Muslim state. He seems to be relatively less informed about that country. Indonesia’s Islamic community is quite moderate, though many Indonesians have become considerably stricter in their religious practice. Surely it was worth examining to what extent Indonesia’s Sunni Muslim community felt both the absence of a single distant caliph and the need to revive the caliphate by supporting the claims of ISIS leader Abu Bakr al-Baghdadi to the caliphate.

Laurence also has little to say about Indonesia’s neighbor, Malaysia, a majority Sunni Muslim state with Islam written into its constitution. Like Indonesia—indeed, even more so and over a longer period—Malaysia has become increasingly Islamized. The author does not examine these trends, much less their cause. The reader is left to wonder whether Malaysian Muslims, or their Indonesian counterparts, for that matter, ever looked to the Ottoman caliph for spiritual leadership, and whether the absence of a central Islamic authority in any way explains whatever radicalization has manifested itself among Muslims in either country.

Perhaps even more surprising, Laurence does not devote the same in-depth analysis of developments in Egypt as he does for the francophone North African states. Yet Egypt is the Arab world’s most populous country and for centuries has been its cultural leader and, in the form of Al-Azhar University, the leading center of higher Islamic studies. Laurence did not conduct a single interview with an Egyptian, although he might have met not only with both Egyptian government officials and opposition leaders, but also perhaps with those members of the Muslim Brotherhood who escaped the country after the 2013 military takeover. He might also have interviewed Coptic Egyptians who have, on the one hand, had leading roles in many Egyptian governments yet have been subject to victimization as well. He did none of these things.

“Egyptian Islam’s multiple layers of authority,” he writes, “proved too unwieldy to fit neatly into this comparative work.” Surely, if that is the case, perhaps the premise underlying the work requires some adjustment. Laurence adds that he “also shied away from fieldwork in Egypt or Libya during the turbulent decade of the 2010s.” While he could certainly justify keeping clear of Libya once it became engulfed in a civil war that has yet to be resolved, Egypt has been stable since the Muslim Brotherhood fell from power in 2013. His explanation rings somewhat hollow.

IT IS understandable that Laurence was concerned about traveling to unstable societies suffering from endemic terrorism. That would explain not only his concern about undertaking research in Libya, but also his avoidance of Somalia, whose population is 99 percent Sunni. It does not explain his failure to examine Indonesia and Malaysia, which, like Egypt, are relatively stable. And most notably, it does not explain his neglecting to examine Saudi Arabia in any great detail.

Saudi Arabia, like Egypt, plays no more than an ancillary or at best supporting role in Laurence’s narrative. He views the kingdom’s efforts to spread its Wahhabi version of Sunni Islam as essentially subversive, if not the primary source of contemporary Islamic radicalization, especially among younger Muslims. He acknowledges the Saudi king’s role as Custodian of the Two Holy Mosques of Mecca and Medina, but implicitly challenges the al-Saud claim to that role since the family is not directly descended from the prophet. In truth, it makes no claims to that effect.

Whether Laurence’s characterization of the Saudis and their royal family is accurate is another question. He does not demonstrate to any quantitative degree that radical Islamists were influenced by their attendance at Saudi-sponsored madrassas. Not all Saudis who joined radical Islamist groups were from the disadvantaged classes: the majority of the 9/11 hijackers were middle-class Saudis. And surely not all Saudis who have joined ISIS—Saudi Arabia is the second-largest contributor of foreign fighters after Tunisia—were drawn from the country’s poor. It is also noteworthy, as Laurence himself points out, that the al-Saud family has been the target of radical Islamists, among whom the Yemeni-born Osama bin Laden was certainly the most notorious.

Given Saudi Arabia’s central role in Sunni Islam, indeed in all Islam, as the host of the annual hajj and the king’s role as custodian of the religion’s two most holy sites, Laurence surely should have paid far more attention to the desert kingdom. His explanation for not focusing more on Egypt certainly does not apply to Saudi Arabia, where there are few if any “multiple layers of authority.” Precisely because his primary focus is on majority Sunni former Ottoman territories, Laurence certainly should have devoted at least a full chapter to the kingdom.

THERE ARE other nations of note that stand out in their absence. Laurence has relatively little to say about Jordan, which, like Saudi Arabia, was under Turkish Ottoman rule as part of the Syria vilayet, or province. He does address the role of Emir Faisal, the founder of Jordan’s ruling Hashemite dynasty, but subsequent to the country becoming independent it virtually drops from his radar screen. Yet King Abdullah II remains the custodian of Islam’s third holiest site, the Al-Aqsa Mosque. Moreover, relative to the country’s population, Jordanians have comprised the largest single group of foreign fighters under the ISIS flag.

Nor did Laurence examine in greater depth whether those men who joined ISIS did so because they felt a need for a universal caliphate, or whether their motives were far less exalted and focused instead on war, wealth, and women. Was the problem of “multiple layers of authority” here as well? As in the case of Saudi Arabia, the author does not even bother to explain why he did not include Jordan in his analysis.

Pakistan is yet another Sunni-dominated state that Laurence completely overlooks. He includes passing references to India’s Muslims, but none to Pakistan’s, although Pakistan broke away from India precisely so as to become a sovereign Muslim state. Laurence could have focused on the attitudes of Pakistanis after partition and explored the degree to which Saudi-supported Wahhabi influence on the country’s ubiquitous madrassas, coupled with a longing for a new caliph, led to the support that many Pakistanis gave to the Islamic State. Laurence does not even bother to explain why he did not attempt to interview Pakistanis, or examine Pakistan, in-depth.

Laurence limits his relatively brief discussion of the Indian Muslim minority, which comprises the world’s third-largest Muslim population, to pre-independence India. Perhaps he does so because India’s Muslims are a minority. Perhaps he does so because in the aftermath of World War I there was a movement in India to preserve the Turkish caliphate. A century has passed since that movement was at its height, however. It certainly would have been worth asking, as Adil Rasheed, a research fellow at the Manohar Parrikar Institute for Defence Studies and Analyses in New Delhi put it:

How can a country with the third-largest Muslim population in the world, which was partitioned over the issue of Islamism; has had a history of communal violence since independence; suffered a spate of terror attacks by homegrown and Pakistan-backed terrorists in recent decades; witnesses a continuing insurgency in the Muslim-majority Kashmir; and whose polity is still deeply divided over the Muslim question produce fewer adherents of ISIS and Al Qaeda than many Western states having a much smaller Muslim population?

Out of a Muslim population that exceeds 172 million, only 100 joined ISIS. Rasheed argues that 

…the call for reinstituting the Caliphate also does not appeal to most Indian Muslims. This is because Indian Muslim rulers never paid allegiance to any West Asian caliph, nor did they send their forces to foreign lands to fight for the glory of Islam.