Although perhaps it is unfair to castigate a book based upon a clause in one sentence, Simms really should know better. As far as I can parse out, Simms's argument is that by being checked by the West, the Ottoman Empire turned inwards as this defeat was a clear sign the empire was no longer expanding. This necessitated a selective import of Western ideas and other non-Islamic innovations to shore up Ottoman power. This incomplete secularization in turn stimulated an ideological retrenchment, especially in the Arabian peninsula by Muhammad ibn Abd al-Wahhab to restore the religious purity of the Islamic world. Thus, Simms writes "the religious radicalization of the Arab world, in other words, began in central Europe, before the walls of Vienna."

While this makes for a neat and digestible narrative, it is an unsupportable thesis. "Radical Islam" is a very freighted and problematic term, and it should be used cautiously by historians, if at all (more accurately, one could speak of radical Islams rather than considering it as a single movement). The problem with Simms's narrative is that he is connecting developments in Islamic theology with larger geopolitical struggles when the facts really do not fit the case. One of the chief Islamic scholars and jurists that preached for a return to the roots of Islam was Ibn Taymiyyah, who lived a good three centuries before the last siege of Vienna. Taymiyyah's thoughts preaching on Islamic revival were very influential on al-Wahhab and percolated in various Islamic circles. The revivalism preached by Taymiyyah did not come from the either either, and the history of medieval Islam is filled with various movements and thinkers who called for a return to the Islamic values of the Prophet and decried the irreligiousity of those in power. And of course, the theology and movements often associated with radical Islam (eg Muslim Brotherhood, Hezbollah, etc.) have their origin points in the late nineteenth and twentieth centuries, and while Wahhibism has been an important component for these groups, they are a rather heterogeneous lot. Reducing religious radicalization to a single origin point in the seventeenth century is a haphazard way to write about the evolution of a complex and diverse movement.

Simms's location of Central Europe as the origin point for this evolution in Islam is also quite shaky. There is a long tradition in the West to frame the history of the Ottoman Empire in terms of its relationship to the West. Therefore, if the Sultan's armies are on the march in the Balkans, the empire is strong and rising. Conversely, this paradigm holds that if the empire sees a reverse in Europe like Lepanto, then it is retreating. What this does is privilege European history over Ottoman history, when the reality was that Europe was only one of several areas of interest for Topkapı. Reverses like Lepanto and Vienna were unwelcome, but they were a part of a larger geopolitical ebb and flow. What happened in Egypt or on the border with Persia was just as important, and in more than a few cases, more important for Ottoman power than its struggles with the Habsburgs. While older historiography prioritized a narrative in which the rise of Islam is one of Islam versus the Christian West, current scholarship has been downgrading the importance of Europe to the medieval and early modern Islamic world. The Battle of Tours may have been important for the Carolingians, it was not that central to the overall power of the overstretched Umayyads. Taymiyyah's own call for theological revivalism came not from the legacy of the Crusades, but from the Mongol invasions, which far overshadowed the Crusades' importance for many of Taymiyyah's contemporaries. The issue of Ottoman decline is a highly contentious one inside Ottoman historiography and one of the ongoing trends in scholarship is to try and pull out the Eurocentric weeds of older works. This fosters a much more nuanced view of the Ottoman past. By looking at domestic and non-European factors, for example, the rise of Wahhabism emerges not just as a reaction against European encroachments upon Ottoman power, but also due to the shifting internal politics of the Arabian peninsula as well other domestic problems within the empire. By attaching such importance to the Viennese sieges, Simms is carelessly reifying a paradigm that Ottoman historiography has been moving away from for quite some time.

And this leads us back to "he should know better." As a specialist in German history. Simms should understand the ramifications of taking modern political movements and tracing their origins back centuries. In German historiography there is a pernicious demon called the Sonderweg which posits that Germany followed a special path from "Luther to Hitler" that encouraged illiberal thought and other anti-democratic tendencies. This model stresses abnormal development and malformation, denies German history of any sense of contingency and often relies on a sketchy process of taking Hitler and tracing back the various links between German history and National Socialism. While it is important for historians to examine the intellectual and social parentage of National Socialism, the Sonderweg is often predicated upon the inevitability of Hitler or someone like him. This skews the analysis of the German past, ignoring contingent factors in the rise of Hitler as well as the real differences between, say, the antisemitism of Luther and that of Julius Langbehn. Although the Sonderweg has proven as hard to kill as a 1980s slasher villain, most mainstream German historians reject such a long-term schematic interpretation of German history. The rise of radical Islam was incredibly complicated and locating a single starting point for it is methodologically dubious and falling well outside the trends of scholarship in Ottoman and Islamic history.