Do Good Fences Make Good Neighbors? addresses the historical impact of strategic barriers, defined here as "continuous or mutually supporting works denying the enemy avenues of attack across a front." In his introduction, Brent Sterling argues for the relevance of such an appraisal given the renewal of interest in strategic defense around the world (old fashioned walls, as well as more novel missile defenses) and the shallow debate surrounding it, the "dynamic" of which "is for critics and proponents to talk past each other, adding highly subjective versions of the past to bolster their arguments," with even normally circumspect historians "prone to apply sweeping characterizations on this topic."
That problem is in all likelihood a byproduct of the paucity of serious research on the subject of fortification in recent years. (An examination of Parameters' index of books reviewed between 1996 and 2010, for instance, shows only one dealing with the topic, Breaching the Fortress Wall, a RAND Corporation monograph from 2007 focused on the vulnerability of modern infrastructure to terrorism.) By and large, the available literature examines particular defensive works, conflicts, or periods (for instance, Medieval castles or Civil War forts), or is part of broader histories of wars and warfare (such as John Keegan's 1992 A History of Warfare, which Sterling cites three times in his discussion of basics in his first chapter—a reliance that is telling).
Naturally, serious book-length studies offering cross-cultural comparisons, or dealing specifically with strategic barriers as a class, are even rarer than writing on fortification in general, which is by itself enough to make Sterling's book worthy of attention. The interest of the book is reinforced by its particular approach to the subject matter, emphasizing the effect of such defenses on the behavior of major actors involved by way of three central questions: first, how the barrier affects "adversary perceptions of the building state's intent and capability," and how it shapes their subsequent behavior; second, the effect of the system on the immediate and long-term "military balance"; and finally, the influence of the barrier on the "subsequent outlook, policy debate, and behavior within the organizing state."
In trying to answer these questions, Sterling opts for in-depth examinations of a half-dozen cases, each a situation in which plausible alternatives to barrier-building existed. Accordingly, he excludes defenses hurriedly thrown up in wartime, or those made unavoidable by the weakness of the building power compared with its adversary (as with the World War II–era German Gustav Line and Finnish Mannerheim Line, respectively). Making the final cut are ancient Athens's Long Walls, Hadrian's Wall in Britain, the Ming Dynasty's Great Wall, Louis XIV's Pre Carre, the French Maginot Line, and the Israeli Bar-Lev Line.
Ultimately, Sterling concludes that barriers are neither useless nor a panacea. Properly constructed barriers are frequently effective militarily, imposing costs on hostile penetrations, slowing enemy advances, forcing the attackers to change their behavior in significant ways (such as by seeking ways around the barrier), and offering other uses (such as providing a base for forward operations).
However, barriers are costly to adequately build, maintain, and man, enough so that the builders commonly fail to sustain the required investment over time. Sterling also notes the tendency of the military balance to shift away from the wall-builders over time, as their opponents learn to circumvent or overcome the barriers (a problem that may have worsened with the increasing rapidity of technological change in modern times), while the "deterrence by denial" that the barriers provide must often be backed by "deterrence by punishment" in the case of highly motivated opponents.
More fundamentally, strategic defenses cannot substitute for a sound strategic orientation toward both allies and opponents, who can be alienated or even antagonized by the barriers. Additionally, such barriers can foster a sense of "subjective" security that reinforces existing tendencies in behavior that may be inappropriate to a given situation, such as excessive risk-taking or the avoidance of deeper solutions to problems that arise (political or military), which also raises the risk of disproportionate demoralization when the sense of invulnerability the barriers provide is punctured by their failure.
Sterling concedes the limits that a single researcher faces in dealing with such a wide range of subject matter in his introduction, and at the same time, the limited diversity of the cases (with four of the six involving European conflicts), but his individual chapters are comprehensive in their treatment of their subjects, running a dense 40 to 50 pages each (counting notes), while offering enough range and depth for a search for historical lessons. Together, along with the concise chapter in which Sterling offers his conclusions, they make for a robust, lucid, and persuasive (as well as accessible) examination of the issue.
It might be protested that the cases Sterling examines bear little relevance for current debates about strategic barriers, which are less concerned with thwarting invading armies than controlling population and material flows (with respect to issues like illegal immigration)—a matter Sterling brings up early on but devotes little space to (and none at all outside of the Roman and Ming cases). However, much of Sterling's broader analysis (for instance, regarding the changes forced on behavior by a wall's presence, maintenance costs, and impact on perceptions) is applicable to those matters as well, and readers primarily interested in those issues can also expect to find the book worth their while. Do Good Fences Make Good Neighbors? is a solid start to a sounder debate about this important subject and is likely to prove essential reading for students of its subject for years to come. JFQ