To paraphrase Martin van Creveld, before the mid-twentieth century, conquering a country was usually a hard, lengthy process, but occupying it in the aftermath was relatively easy; by the time of World War II, countries might be conquered more speedily, but holding onto them has proved difficult indeed.

A crucial component of this historical transformation was the heightened role of guerrilla warfare and the kind of asymmetric situations that have tended to characterize warfare since 1945. Ben Shepherd's Terror in the Balkans is a case study of one such situation, and a classic one: the terrible German, Italian, and Ustasha occupation and counterinsurgency war in the lands of Yugoslavia. Shepherd studies precisely the mechanism of the trend to which van Creveld was referring. In particular, the author has investigated the division-level—middle management—policies of the German army commands entrusted with “keeping the peace”—or rather, with fighting the insurgency—in the post-conquest zones of Yugoslavia from 1941 to 1944.

As with Shepherd's 2004 study, War in the Wild East, this work is especially concerned with the leadership of the regiments, divisions, and army corps involved in fighting insurgents. One of Shepherd's central points is that if all the mid-level commanders in the Balkans were brutal and indeed under orders to carry out brutal policies of repression, it was still the case that some behaved more brutally than others. Terror was, of course, the name of the game. The horrific reprisal ratio of the Germans in Yugoslavian occupation—shooting one hundred local villagers or townspeople in exchange for the life of one ambushed German soldier—is well known, not least because of its role in the mechanics of the Final Solution (long since studied by Christopher Browning and others). Yet Shepherd demonstrates that although this horrific policy was predominant—especially in times of emergency—it was not a constant. Documents show that the famous ratio did not apply all the time and in all sectors, and that some of the commanders resisted the brutal measures being forced downward from the army command in the theater and even higher—more than once from Hitler himself.

Shepherd follows this variation in levels of ferocity to flesh out two different sub-themes. First, he is interested in tracing the origins of the most brutal officers’ enthusiasm for violence against Serbs, Jews, Roma, and Sinti, and others. He finds a correlation between the most ferocious generals in the German Balkan divisions on the one hand, and individual service against the Serbs in World War I on the other. Most, but not all, of these officers had been in the Austro-Hungarian army. As with the German Eastern Front of the First World War (demonstrated in Shepherd's own previous work as well as in Liulevicius's War Land on the Eastern Front and others), the “Schrecklichkeit” policies of 1914 were intensified by notions of strangeness and barbarity among the conquered populations. During World War I, the k.-and k. army, as Shepherd shows, was bitterly impressed with the “inhumanity” and brutality of the Serbs.

Shepherd maintains that this “history” played a crucial role in the terror policies of 1941 and after. The commanding general of the Serbian theater (Franz Boehme) made this connection in an order issued just after the invasion of the Balkans: “Your objective is to be achieved in a land where, in 1914, streams of German blood flowed because of the treachery of the Serbs, men and women. You are the avengers of those dead” (p. 2).Yet for most of the generals Shepherd studies, such direct evidence of the link between 1914 and 1941 is rarely available. As Shepherd makes clear, it would have been helpful to have some harder evidence as to the exact nature of the connections between service in Serbia in 1914–1918 and to ultra-terroristic polices in the Balkans in 1941–1944. But in general, the correlation laid out by Shepherd certainly makes sense. It certainly fits into the larger pattern now emerging in the literature on violence in the period of World War II.

Another secondary focus relating to the differentiation among German officers is the dynamics of the counterinsurgency. In this regard, Shepherd's study of divisional decisions, tactics, and results provides a really valuable analysis of what worked and what did not. Shepherd does not explicitly place his monograph within this broader context of the history of asymmetric warfare, but the reader is certainly at liberty to do so.

We find, for example, that highly terroristic policies were recognized by moderate officers as ineffective, wasteful of troops, deadly for innocents. Many of these same officers decided, at least at some point in the conflict, to cultivate a “hearts and minds” approach, ordering their troops to engage in activities such as cultivating relationships, helping with food supplies when possible, and the like. In a similar vein, a major part of the counterinsurgency program, Shepherd shows, was the attempt to raise and train local units to keep the peace, especially against the Communist Partisans, who were quite capable of carrying out their own kind of terror, often against noncomplying civilians.

Although the author leaves no doubt that German brutality in Serbia, Bosnia, and Croatia created horrifying desolation, his study points up the wide variety of problems facing any country at this stage of human history that chooses to invade and occupy another, whether it embraces terror policy or not.

The history of the lands of Yugoslavia during period of World War II has always been marked by baffling complexity, for contemporary observers as well as historians. Shepherd's account adds to the detail and richness of the picture. But paradoxically, Shepherd manages to simplify this complicated story in striking ways. A careful framework allows Shepherd to explain the complicated relationships between the German army, the Italian occupiers, the Ustasha regime, Tito's Partisans, Mihailovich's Chetniks, and many other groups clearly and effectively. This clarity constitutes another important aspect of this important book.