Is there a global international society? Has it grown stronger or weaker as it has become more post-Western? Faced by US-China tensions, the decoupling of globalization, and the challenges to global governance and national societies from the global pandemic, how can we make sense of the many claims and counterclaims and try to discern in which direction global international society may be moving?

The core aim of this book is to provide a conceptual set of tools for engaging the problem of international society at the global level. Its goal is to combine taxonomy with criteria for judging strength and weakness. Its focus is on how we can think of the global in holistic and social terms. As the authors write at the outset, “Everyone needs to be able to specify what the ‘whole’ is that we attempt to discern when we adopt a global social perspective” (p. 1). And they are refreshingly unrepentant about the complexity of the task. The subtitle of chapter 7—“The Complex Differentiation of Contemporary Global International Society”—gives a flavor of the bottom-line argument. English School writing was born out of a sense of frustration with the tired debates of the mid-twentieth century between realism and liberalism—and this frustration surely remains, given the equally sterile debates between those who see nothing but a new Cold War between the United States and China and those for whom global order is simply about the defense of the mythical liberal order of the post–Cold War years.

Barry Buzan and Laust Schouenborg begin by drawing together an impressively wide range of writing, mostly within the English School or international society tradition, and identifying five strands of previous work, including the important distinction between primary and secondary institutions and the growth of work on regional international societies. They then provide a succinct and analytically sophisticated framework for understanding how international societies expand and for retelling the old story of the “expansion” of Western or European international society. In doing so, they explore four submodels: unbroken creation, repopulation, colonization/decolonization, and encounter/reform. The central chapters of the book explore four models for making sense of what global international society has become: the like-units model, the regional/subglobal model, the hierarchy/privilege model, and the functional differentiation model. In each case the model is laid out and then followed by a discussion of its strengths and weaknesses: How well does it capture the actual nature of the units? How well does it capture the actual nature of the structure? How well does it capture the binding forces? Chapter 7 seeks to aggregate the models, examining the strengthening/ weakening question around 12 criteria.

In addition to the richness of the taxonomies, the clarity with which questions are posed, and the sharpness of the criteria for evaluation, many of the core judgments about the direction in which global international society may be moving seem right. There is, for example, an admirable insistence that the move to a more decentered globalism is not solely about the “rise of China.” And there is a recurrent and powerful emphasis on deep pluralism as one of the most important features of the contemporary global order: “As other cultures find their own accommodation with the revolutions of modernity, the West will remain strong, but no longer dominant. This development is not just about China, though China is a big part of the rise of the rest. It is about the evening out of power and authority as the rest of the world recovers its position after the extraordinary inequality created by the rapid consolidation of modernity in a handful of mainly Western countries during the nineteenth century: what we labelled previously as ‘deep’ or “embedded pluralism”’ (p. 68).

Occasionally their judgments jar. Class, we are told, “appears to be a nonissue for GIS” (p. 144). Why? Apparently because the market is an unchallenged primary institution of global international society. But markets and political economy assume many different forms, and more importantly for a book on the global, capitalism is not just about markets. It was one of the driving forces of the modern global and one that has continued to produce both recurrent crises and instability and structured patterns of wealth and inequality, both within and across societies and in terms of the distribution of interstate power. Meshing dangerously with the claims and resentments of identity politics, class has surely been one of the major drivers of recent backlash politics and authoritarian nationalism. The authors correctly stress the foundational role of the great revolutions of modernity of the nineteenth century, and yet the changing nature of the global and shifting understandings of the modern global remain somewhat underdeveloped.

The book is very much written from within the academic world. There are dense thickets of concepts, models, criteria for success, and abbreviations, and the writing is not always easy to follow; for example, “As if this massive tension between LUM and HPM was not enough, the version 1.0 colonial GIS also contained an element of the FDM” (p. 188). Or, “Increasing the proportion of solidarist to pluralist PIs within GIS strengthens it according the LUM and its inherent logic of convergence. However, whether solidarist PIs have this effect in general has turned into a very complicated question. The RSM and HPM are basically agonistic about the effects of solidarist PIs, recognizing their Western normative baggage” (p. 195). Even for the attentive reader and for someone well versed in the background literature, this is a book that would have benefited from better editing. For all the need for complexity, the authors at times simply seem to be trying to pack in too much, as for example in their discussion of the differentiation of units and of types and forms of states (pp. 59–69).

Even before COVID the old world was under challenge, yet discerning the outlines of the new was fraught with uncertainty. This book does not provide answers, but it does provide a rich repository of conceptual tools from which others can profitably draw and apply as part of their own arguments. Although the goal is explicitly analytical and not normative, it also makes a series of concluding observations that strike at the heart of current debates and that the authors see as providing some grounds for optimism, First, “this emerging structure will not be multipolarity as classically understood because, lacking any superpowers or aspiring to be superpowers, it will not feature a realist-type struggle for domination of the whole system” (p. 192). Second, “deep pluralism points towards a two-tier international society in which the global level is mainly concerned with shared fate issues, the regional level is mainly concerned with promoting and defending regional political and cultural differentiation within the context of some form of on-going global economy” (p. 192). Finally, and perhaps most importantly, “deep pluralism can itself become a source of strength for GIS provided that the powers accept pluralism as the foundation for common primary institutions” (p. 209).