Thomas Hale has produced a valuable analysis of the woefully understudied regime for transnational commercial arbitration (TCA). The book should appeal to lawyers and political scientists interested in the workings of the highly variegated institutions of the international political economy.

Theoretically, Hale contrasts a rationalist logic of material interests (“market power”), grounded in political economy, with an ideational logic of legitimacy (“legal networks”), grounded in sociolegal precepts. Wisely, he never insists on framing these rather standard alternatives as strict opposites, but carefully identifies observable implications, draws special attention to differentiating (as opposed to observationally equivalent) empirical terrain, and carefully weighs and sifts the two types of factors. The theoretical apparatus, aimed at explaining institutional variation—and, in particular, the neutrality, efficiency, and authority of commercial arbitration institutions—is quite involved, extending to both institutional supply and demand, and covering public and private alternatives at domestic, interstate, and transnational levels of analysis. Roughly speaking, rationalists expect firms to demand features that correspond to their functional needs, and expect institutional supply to reflect these (power-weighted) preferences. The legal networks approach is less elaborated, but emphasizes the degree to which fields exist that, through processes of legal contestation between epistemic communities, have developed and entrenched legal norms that exert isomorphic pressure on firms and policymakers.

The study’s greatest strengths are empirical. The book teaches us a tremendous amount about a complicated and important issue that has been studied by lawyers, historians, and policy analysts more than political scientists, an understanding of which has been more oriented toward practice than engagement with theoretical questions around global governance. Hale is veritably encyclopedic, mapping the evolution of an intergovernmental regime over the course of the twentieth century and, in separate chapters, those regimes developed in the United States and Argentina through their colonial and postcolonial histories and that of China from the mid-nineteenth century to the present. I expect that many interested in the substance of TCA will keep the book handy as an empirical reference.

Several key takeaways emerge from the encounter between theory and evidence. First, the market power explanation is, overall, the more powerful in explaining basic institutional architectures. Second, legal networks can better account for narrow-gauge institutional design features that material interests underdetermine. Third, while politics is always first out of the gate, acting decisively in the early stages of regime formation, law comes to exert greater influence over time, as institutionalization deepens. Fourth, while powerful market actors may tolerate some normative drift, politics constrains law.

These are worthwhile findings that can serve as a productive basis for engagement by other scholars. In particular, Hale models and promotes interdisciplinary dialogue of a sort that remains far too rare, and which can bear real fruit. Yet this task will be made more difficult given some of the book’s problems, and primarily the need for additional sharpening. For one thing, Between Interests and Law could have used more editing, which, of course, is a responsibility only partly falling on the author. Typos proliferate from about 150 pages in. More importantly, the book is just too long, with the chapters on the United States and Argentina clocking in at 75 and 70 pages, respectively, and contains many lengthy, detailed accounts of negotiations that reflect great historical research but do not necessarily shed theoretical light. The comparatively svelte China chapter includes a section (7.4.2) on the scope of commercial arbitration practices in contemporary China with the same qualities. In this light, Hale’s very laudable comprehensiveness constitutes a double-edged sword.

With respect to theory, the “market power” hypothesis sometimes stands as a form of generic rational materialism, whereby any interested action, as for example growing use by firms of increasingly effective arbitral institutions in China, is taken as confirmatory of the market power hypothesis (p. 339). This represents something of a missed opportunity, because the theoretical chapter offers many very insightful ideas that sharply center on market power, how it might lead states to prefer different mixes of neutrality, efficiency, and authority in arbitral institutions, and how they might strategically pursue these derived interests among public and private alternatives at different levels of analysis. Sometimes the analysis fails sharply to distinguish itself from a simpler “rational design” logic linking functional imperatives to institutional features. For example, Hale repeatedly finds, and claims for the market power approach, that commodities markets, characterized by a small number of players engaged in repeated interactions over relatively uniform goods, do not need elaborate arbitral governance, since disputes rarely occur and when they do, can generally be relatively easily settled and reputationally enforced. By late in the book, Hale is discussing a “functionalist version” (p. 340) of his key rationalist hypothesis that did not appear in the theoretical discussion.

I commend Hale for taking comparative theory evaluation seriously. Yet despite the care he takes to operationalize his theoretical constructs, the evidence does not always discriminate as clearly as the author might like. For example, in the Chapter 4 discussion of the 1920s Geneva treaties negotiated around the League of Nations, Italian legal scholar Roberto Pozzi plays a large role, which is discounted through the assertion that “though individual lawyers participated in the drafting of proposals, it was business groups that pushed the ideas” (p. 95). Slightly later, the treaty outcomes are characterized as a hybrid of legal and commercial arguments, but commercial interests again get the credit. In the U.S. chapter, the activities of the Arbitration Association of America (AAA) are sometimes interpreted as business lobbying and other times as lawyerly, a difference that the short assertions (on pp. 202 and 230) do not satisfactorily pin down.

At the same time, explanations that do not fit either the market power or legal networks frames are never seriously engaged as theoretical alternatives. Hale frequently implies that in the absence of rationalist action, legal mechanisms must be operating, or vice versa, as if these are the only two options. The absence of rational demand for the 1958 New York Convention (p. 140), or the absence of preconditions necessary for the operation of legal networks on China (p. 317) provide two examples. Domestic politics is considerably undertheorized as the vector sum of the social forces (firms), but in the historical narratives it is clear that ideology (e.g., American isolationism in the 1920s), domestic institutions (American federalism in the same period, variation in Argentine state strength throughout history), external political pressure and market competition (early republican Argentina), and regime interests (China in the contemporary period) all matter and sometimes play key explanatory roles. We cannot cover every base, of course, but the book might have produced clearer theoretical conclusions if it had taken these factors more seriously, rather than narrating them without comment.

Despite these criticisms, Between Interests and Law reinforces the observation that far from the imagined anarchy of realist theory, international relations embodies a rich multiplicity of public, private, domestic, international, and transnational institutions, and hybrids blending all of these that govern, often minutely, issues of massive importance to all of us. It also underscores that there is work to do, drawing on as many disciplines and traditions as necessary, to make sense of this global polyarchy.