The life sciences and social sciences typically study “complex adaptive systems:” nonlinear, self-organizing, adaptive, multilevel, multicomponent systems in which dense interconnections between elements produce irreducible/emergent systems effects. Systems and their components are partially (in)separable: they can be fully understood neither solely in terms of their parts (some outcomes are emergent) nor solely in terms of the whole (the character of the parts is essential to the nature of the whole). Important implications of a complex adaptive systems perspective for IR include a new view of international systems and their structures; a distinctive understanding of social continuity and social change; new perspectives on levels, theory, and explanation; new tools for comparative analysis; renewed attention to hierarchy; and a distinctive understanding of globalization.

Multilevel multicomponent complex adaptive systems are not reducible to the sum of the causal effects of independent variables. Causal inference, which has a privileged place in contemporary IR (and many other social sciences) cannot address systems effects, which arise from interdependent elements and operations (not the impact of independent variables on dependent variables). Systems effects explanations explain why by showing how. They identify mechanisms and processes of causation. They thus are able to establish causal efficacy; that is, show how processes produce – actually cause – outcomes (rather than merely identify some elements that are part of an unspecified causal process). Such an understanding leads us away from a “laws and theories” conception of science, which remains popular in Physics and Chemistry, towards a “models and mechanisms” understanding, which predominates in the life sciences (which, on their face, seem a much better model for the social sciences).

This chapter discusses the basics of the law of treaties: what they are, how they are concluded, what efefcts they generate, and how they are to be terminated. It is built around the 1969 Vienna Convention on the Law of Treaties

How international (and other social) systems are stratified – how social positions are arranged in ranked relations of super-, sub-, and co-ordination – is obviously central to their structure and functioning. This chapter looks at two broad types of vertical differentiation: single (or convergent) hierarchies and heterarchies (or multiply ranked orders). I begin with a 2x2 typology of hierarchies, based on whether they are restricted to a single issue or institution and whether they have a single axis of stratification. Among multi-layer systems, which are the norm in international relations, I look at various types of “states systems,” which have different types of relations between more or less autonomous polities; “imperial” systems, which have a single axis of super- and subordination; and “heterarchies,” which have multiple axes of stratification. The chapter concludes by considering the distinctive ways in which typologies explain.

Why are progressives often critical of US foreign policy and the national security state? What would a statecraft that pulls ideas from the American left look like? Grand Strategies of the Left brings the progressive worldview into conversation with security studies and foreign policy practice. It argues that American progressives think durable security will only come by prioritizing the interconnected conditions of peace, democracy, and equality. By conceiving of grand strategy as worldmaking, progressives see multiple ways of using foreign policy to make a more just and stable world. US statecraft – including defense policy – should be retooled not for primacy, endless power accumulation, or a political status quo that privileges elites, but rather to shape the context that gives rise to perpetual insecurity. Progressive worldmaking has its own risks and dilemmas but expands how we imagine what the world is and could be.

This and the following four chapters address the systemic/structural theory of Kenneth N. Waltz. Despite extensive criticisms of its details, Waltz’s account of the nature of system, structures, and systemic/structural theory continues to predominate in contemporary IR. This chapter shows that, despite its systemic starting point, Waltzian structural theory is thoroughly analytic. Waltz replaced components arranged and operating as parts of a structured whole with a reified structure that exerts causal effects on units that interact with one another and with the structure. The resulting one-sided explanation of the actions of “units” by “the system” reduces systems to mere environments of autonomous actors (whose activities are not constituted, generated, or structured by being parts of a system but are simply constrained by external “system-level” forces).

Mainstream social science, when it looks for parallels with the natural sciences, tends to look to classical Physics, which stresses laws, causes, and theories. I argue that we should look instead to Biology, which explains principally with processes, mechanisms, and models. Here I look briefly at Evolutionary Biology and Developmental Biology, where reductionist gene-centric explanatory programs have failed – decisively and spectacularly (and relatively recently). Evolution involves not just genes (let alone selfish genes) but multilevel processes of modular tinkering, very much like what I have called continuous (trans)formation, including processes of co-evolution that are strikingly analogous to what we see in the social world. Similarly, gene expression, rather than a largely mechanical DNA-directed bottom-up process, is as much a matter of manipulating and transforming genetic material as it is processing the information that it contains. Gene expression can only be properly performed within multiple, complexly intertwined, self-organizing regulatory networks. More broadly, I argue that Systems Biology, which is on the cutting edge of twenty-first-century Biology, provides an attractive model for relational/systemic social sciences.

Why are progressives often critical of US foreign policy and the national security state? What would a statecraft that pulls ideas from the American left look like? Grand Strategies of the Left brings the progressive worldview into conversation with security studies and foreign policy practice. It argues that American progressives think durable security will only come by prioritizing the interconnected conditions of peace, democracy, and equality. By conceiving of grand strategy as worldmaking, progressives see multiple ways of using foreign policy to make a more just and stable world. US statecraft – including defense policy – should be retooled not for primacy, endless power accumulation, or a political status quo that privileges elites, but rather to shape the context that gives rise to perpetual insecurity. Progressive worldmaking has its own risks and dilemmas but expands how we imagine what the world is and could be.

This brief “chapter” restates the case for a pluralistic IR that gives substantial attention to the multidimensional structures of relations in international systems; the configuring configurations that configure layered systems of polities.

This chapter, which is by far the longest in the book, looks at the Eurocentric political world over the past eight centuries employing the spatio-political typology sketched in the preceding chapter and the frame of continuous (trans)formation presented in . I argue that on time frames of multiple centuries, dramatic change often is evident. But on time frames of several decades, continuity usually is much more evident. Furthermore, the processes that produce continuity and those that produce change are inextricably interrelated. For reasons of space, I focus especially on the early modern period, which I argue was less “modern” than a middle age between the medieval and the modern world. And rather than depict the rise (and demise) of modern states, I see a succession of different types of polities brought about through extensive and extended processes of continuous (trans)formation. The chapter concludes with a spatio-political reading of globalization that I contrast to several leading alternative framings.

This chapter discusses how international alw is made, and how it can be iendtified