Georg Herbstritt is a historian employed by the Abteilung Bildung und Forschung (Education and Research Department) of the German institution that holds the records of the Ministry of State Security (MfS, or Stasi) of the former German Democratic Republic (GDR). This institution is the BStU (Bundesbeauftragte für die Unterlagen des Staatssicherheitsdienstes der ehemaligen Deutschen Demokratischen Republik, or Federal Commissioner for the Records of the Security Service of the Former German Democratic Republic). His book is both a publication of that institution and the published version of his Ph.D. dissertation. It is a thoughtful and informative study of the Stasi's spies in West Germany. Its English title would be West Germans in the Service of GDR Espionage: An Analytical Study. Its survey of spies in West Germany is very detailed—to the point of pedantry at times. It reflects diligent study of most of the records available: those of the spy prosecutions of the 1990s; of the Stasi's domestic security branches (as distinct from those of its foreign intelligence service, the Hauptverwaltung Aufklärung, or HVA); of the HVA's intelligence archive, known as SIRA (System der Informations-Recherche der HVA); of the HVA's district branches in the GDR; and of the secondary literature. It is a useful addition to the library of any historian of intelligence; however, it has too narrow a focus and will therefore not have quite the value for historians that it might.

Its focus is restricted by two factors. The first is unavoidable and familiar to all historians of intelligence: the nature of the source material available. The branch of the Stasi that was most active in West Germany, the Hauptverwaltung Aufklärung, was allowed to destroy its archive in 1990. The HVA had worked hand-in-glove with the Soviet foreign intelligence service, the KGB's First Chief Directorate, and the Soviet Union wanted its secrets to be kept. The BStU has got round this by decoding the electronic archive of intelligence reports which the HVA kept (SIRA, decoded in 1998) and by obtaining from the U.S. Government copies of the so-called “Rosenholz” card indexes (microfilms that reveal the HVA's entire intelligence network from the 1950s until the late 1980s, including its spies in West Germany). The “Rosenholz” records have been available at the BStU for historical research since 2003; however, much that historians would have liked to know about the HVA was shredded in 1990. The fact that the records of the Stasi's domestic security divisions were not destroyed partly compensates for this. These divisions engaged in much spying in West Germany, and their spies featured prominently among those who went on trial in the 1990s. Likewise, the HVA's district branches in the GDR gave crucial support to its spying in West Germany.

The second factor is that Herbstritt limits his study to spies in West Germany who were tried in the Federal Republic in the 1990s (482 in number, plus seventeen others, making a total of 499). He uses this sample to examine thoroughly what kind of people these were: who among them were the most important spies, what their social background and motivation were, how they were recruited and run, how long they spied, and so on. He shows that Günter Guillaume was not as important as once thought, but that Rainer Rupp and Alfred Spuhler did grave harm to the interests of the Federal Republic. The problem with his focus on trials is that, owing to the Federal Republic's very indulgent statute of limitations, the only spies who could be tried were those who were still active when the GDR collapsed. Most of the spies exposed were not prosecuted at all (indeed, most of those still active in the late 1980s were not prosecuted). So the book does not examine the evolution of the Stasi's spying over the entire forty-year period of its life. Herbstritt needed to exploit the “Rosenholz” records more: they would have enabled him to write a more comprehensive study. His book reads more like a work of anatomy than one of history: it considers an object that is largely fixed in time. It leaves out a key dimension of the Stasi's spying: the length of time it had to penetrate West German institutions. This was an important reason for its success. Very few intelligence services are given both a very easy target and four decades in which to penetrate it. What Herbstritt has to say on this subject is very interesting but only appears in a brief section toward the end of the book. His book concentrates too much on setting out information rather than on providing arguments. The arguments he puts are, on the whole, good ones, but too stunted; they needed to be further developed. German historians do not really believe in conclusions, and the book ends with a weak five-page meditation on the significance of what it contains.

That said, the arguments Herbstritt makes are set out with care and clarity and are supported by copious evidence. He shows that the Stasi's spying in West Germany not only harmed the interests of the Federal Republic but also ordinary people—East Germans who wanted to flee to the West, for example. The spies abroad served as political police as well as an ordinary intelligence service. (Although a good point, it sits ill with his focus on trials, in which harm to individuals was necessarily overshadowed by harm to the public interest, this being necessary for conviction.) Herbstritt also demonstrates that, owing to the numerous connections between their peoples, each German state gravely threatened the security of the other. The Stasi won this struggle. Why did the West German secret services not profit as much from the numerous connections between East and West Germans? Herbstritt would have written a more important book had he tried to answer this question; however, his focus on spies rather than spying prevents him from doing so. Since the Russians tried so hard to keep the KGB's secrets, his book might also have considered the extent to which the methods he examines so meticulously reflected those of the First Chief Directorate. His book is instructive but might have packed a bigger punch.