International relations scholars tend to agree that trust and the absence thereof play a key role in explaining cooperation and conflict. Yet what exactly trust is, where it comes from, and how it works are far from clear, and so exploring these questions remains an important task. Michael Jasinski's book takes on this task and, in doing so, fits with a renewed interest in phenomena of trust among IR scholars, from Andrew Kydd (Trust and Mistrust in International Relations, 2005) to Brian Rathbun (Trust in International Cooperation, 2012).

The basic argument advanced in this book is seemingly straightforward: The kind of social trust existing in a society significantly affects how conflict prone that state is. There are two sides to this argument. The first, emphasized in the title, suggests that societies in a condition of “domestic anarchy” are more likely to become engaged in international conflict. The flip side argument is that states whose societies display “generalized” social trust domestically are benign in their dealings with external actors. Jasinski pursues these arguments to supplement the democratic peace and diversionary war theories by “eliminating their shortcomings.” Yet he also admits to the even more ambitious aim of “creating an overarching theory of international conflict” (p. 5) and cooperation, with domestic social trust as a master variable. To a point, the book does that, but not very persuasively.

The book is knowledgeable, well written and clearly structured. It offers an extensive theoretical discussion engaging a wide range of literature across fields, including psychology, and draws heavily on insights from Eric Uslaner's work on social trust (incidentally, so does Rathbun). In order to test his argument(s) empirically, Jasinski employs a mixed-method approach, a growing trend in American political science. Its creative ambition and comprehensiveness are the book's main virtue; they also instill some problems. Overall, the argumentative net is cast too wide to deliver a focused analysis, and some of the knots holding it together are weak. Indeed, what first appears as a simple argument is in fact a rich tapestry of multiple, loosely similar arguments, whose logical path on both sides of the “social trust” variable—the factors accounting for this condition and its behavioral consequences—is not always easy to follow.

One of the author's core points is that “generalized” social trust, defined as faith in “complete strangers” (p. 47), is found in strong states. This is posited against “particular” social trust, said to be a hallmark of the condition of “domestic anarchy” found in weak states. State strength/weakness thus emerges as a key factor, yet despite the author's efforts, it is not defined carefully. Instead, the reader is given an array of vague markers, such as social cohesion, government legitimacy, effectiveness in providing public goods and reducing inequality, establishing and enforcing rules regulating everyday life, and so on. Moreover, the nascent contractual argument is supplemented by another element: namely, the ability of the state to generate a national identity (“effective nation-building”; p. 62). The treatment of this factor and the difficulty in placing it in the argument is indicative. The discussion moves between a) recognizing that nationalism tends to exclude and discriminate, and b) attempting to link national identity to the practice of trusting “perfect strangers,” thus presenting collective identity as both preventing and supporting generalized social trust. Of course, collective identities can form in both exclusionary and inclusionary ways and build relations of (dis)trust accordingly. Yet while the book rightly reminds us that self-esteem does not require treating others as potential enemies, it does not develop an identity-based argument to account for generalized social trust. All the reader gets is the suggestion that such trust arises out of role-play within a system of shared rules (pp. 71–72).

In order to explain the external effects of domestic social trust (or lack thereof), the book uses insights from literature on cognitive bias to suggest that political elites socialized in a particular domestic environment carry its high/low trust attitude into their dealings with external actors (p. 83). Thus, in essence, it suggests that leaders from a strong state approach perfect strangers abroad with an optimistic and cooperative outlook, whereas societies characterized by domestic anarchy will “create leaders with militant or radical orientations” (p. 85) and a paranoid foreign policy. These claims would have greatly benefitted from a more careful discussion than the 10 pages spent on them, and readers will not likely be persuaded. A realist, for instance, would take issue with the reasoning that a skeptical attitude regarding the trustworthiness of other states leads to conflict.

The theory also leaves some important questions unanswered. For instance, little is said about the relational/interactive dimension. Does it matter whether a state with a certain level of domestic social trust faces a state with a lower or higher level? How does it know about this level? In the same vein, how general can the argument be? While the scenario of the “alien encounter” may be useful theoretically, it seems naive to assume that states (their representatives) encounter each other as perfect strangers. What about other factors influencing perception, such as ideologies? And then there is the hint that high-trust states support and respect international legal structures (p. 88), which begs the question of the role that system-level factors play in the argument.

In framing the analysis exclusively as a contribution to the democratic peace and diversionary war theories, the book fails to make use of, and situate the argument in, some relevant IR literature, including recent works on interstate trust, weak/failed states, and psychological accounts of foreign policy. Most unfortunate, for this reader at least, is the missing engagement with the social constructivist literature that has long explored identity- and norm-based arguments of conflict and cooperation. Only Alexander Wendt is discussed here and there, but even his attempt to theorize the overlap between domestic knowledge and transnational cultures of anarchy is not dealt with. On a more general level, parallels to the communitarianism versus cosmopolitanism debate could have been exploited. An engagement with this literature would have focused the argument and clarified its contribution to IR more broadly.

The empirical analysis displays similar strengths and weaknesses. It uses both quantitative and qualitative methods, and in each case the vague definitions of key terms and the broad argument come in handy.

The quantitative study covers the period 1990–2001, is carefully set up, and utilizes a sensible set of databases. The degree of domestic social trust is operationalized as level of corruption within a society, and an effort is made to explain this link. Different hypotheses are tested using a number of plausible control variables, and the closer they come to the main argument—with initiation in militarized interstate disputes (MID) as the dependent variable—the more statistically significant the findings become. This is interesting, although its relevance depends on whether one goes along with reading a correlation between domestic corruption and MID initiation as evidence validating the argument outlined earlier.

It would have been nice to read a case study (or two) from the same period. That the author chose the outbreak of World War I instead can be justified with its status as the litmus test for IR theories of war. Yet it probably is also the most overdetermined event, making a competent evaluation difficult. In his account, Jasinski assesses factors not considered in the quantitative analysis, such as state strength and national identity, through brief studies of the internal configuration of the European great powers involved. Whether one finds these studies convincing depends, ultimately, on whether one accepts the interpretation that Germany, Austria-Hungary, and Russia experienced domestic anarchy prior to the outbreak of the war, and that France and Great Britain enjoyed effective governance and a high level of social trust.

In the end, the creative ambition driving Social Trust, Anarchy, and International Conflict and its attempt to integrate a variety of conceptual and empirical insights make it worth reading. It may not link up to a coherent whole, and its conclusion that international peace requires strong states may stand on thin legs. Still, the book should prompt IR scholars to think harder about phenomena of trust and stimulate new questions about the domestic sources of conflict and cooperation—and that is an achievement.