The traditional story about IR theory is that it is divided into a series of mutually exclusive camps, or “isms,” each of which contains distinct propositions about how world politics works; doing research in IR either means defending one “ism” against the others, or setting up competitive evaluations of various “isms” against one another. Hence we have “realism,” in which sovereign states threaten one another in a dangerous anarchic world, “liberalism,” in which sovereign states bargain with one another in a not-so-dangerous-but-still-anarchic world, and, most recently, “constructivism,” in which norms and ideas influence sovereign states to deal more nicely with one another in a “culture of anarchy” that can vary from cutthroat competition to security community. (Once upon a time there was “Marxism,” but that's largely disappeared from “isms” talk about the field.)
That this picture of IR theory as divided into incommensurable but somehow still comparable camps (sometimes quite misleadingly called “paradigms”) is misleading and counterproductive is fairly well known, but we still operate with the “ism” categories as though expecting them to contain actual substantive content. This is why Barkin's book is so refreshing: the very title transgresses supposedly sacrosanct boundaries, as the book sets out to explore parallels and overlaps that exist where the “isms” story would lead us to expect none. Rather than defining realist and constructivist approaches to the study of world politics expansively, as complete sets of assumptions that must be either completely accepted or completely rejected, Barkin develops more narrow definitions of these approaches as resting on single core concepts—power politics for realism, and the intersubjective production of social order through action for constructivism—that different researchers cash out in different ways. The advantage of such narrow definitions is that they make conceptual sense of “terms that have come to be central to the discipline” and let the use of these terms convey “more information about what a scholar is doing” than the expansive and synthetic packages that few self-professed “realists” or “constructivists” actually adhere to in their totality (155). These definitions—together with the definition of liberalism in terms of the perfectibility of human nature and the notion “that the creation of appropriate social institutions will enable that perfectibility” (115)—also make possible a different conceptual geography of IR theory, in which combinations of core concepts in particular research projects are not forbidden by fiat, but encouraged.
Barkin's presentation does a lot to replace the view of IR theories as “independent castles” with a view of different approaches “as interrelating parts of a matrix” (12). The particular combination he explores in most detail—realist constructivism—is a combination that is made possible by a return to classical realism's focus on prescription, and an abandonment of the contemporary realist focus on prediction; this is necessary because, as Barkin makes abundantly clear, the core constructivist commitment to the active role of agency in producing social arrangements is simply incompatible with the activity of prediction (102–3). But even the return to classical realism doesn't smooth out all of the obstacles to a realist-constructivist union. Barkin neatly disposes of the chimera of ideas vs. material factors by pointing out that the constructivist commitment is to social construction and not to ideational determinism, but he glosses over a major sticking point on the matter of “interests”: prescriptive realism still requires the ability to specify an interest in advance in order to puncture utopian liberal fantasies, while explanatory constructivism demands that any operative notion of interest emerge from concrete social practices. Barkin manages to illustrate only that realism and constructivism have “compatible” notions of the public interest by emphasizing their shared opposition to transhistorical generalization (75), but whether this is enough of a commonality for the two approaches remains an open question.
Indeed, one of the dimensions of theoretical incompatibility that Barkin does not spend much time with involves methodology and the epistemic aims of different kinds of research on world politics. In many ways this is entirely proper, given his focus on defining IR theories in terms of their substantive core content and not in terms of the methodological stances adopted by researchers working with that core content. This is a sensible decision, given that methodology is logically separable from (even if some would say that it is related to) substantive theory. By defining the core concepts of IR theory in a methodology-independent way, Barkin also opens up the possibility of novel combinations of theories and research designs; one cost of doing so is that he overlooks the ways that certain methodologies (like analytical systems theory) can produce, when combined with substantive theoretical assumptions, an even more fertile ground for combining substantive commitments. The contest of “isms” is, in many ways, underpinned by a neopositivist sensibility that demands that claims be tested against one another to ascertain which accounts for the most variation in the outcome of interest, so switching methodological perspectives might advance Barkin's project in ways that the enumeration of core principles alone simply cannot achieve. Although Barkin hints at this in erecting the realist-constructivist alliance on the grounds of classical realism rather than on contemporary realism with its point-predictions about state behavior, he misses an opportunity by not considering the ideal-typical character of Waltz's famous account of international politics; properly understood—and granted, most contemporary realists also misunderstand Waltz's account even as they claim to rely on it—Waltz is making no transhistorical claims and foreclosing no individual agency, because he is concerned to elaborate a structural logic that “shapes and shoves” rather than a parametric constraint on social action. A realist constructivism might also be built on this basis.
Despite any minor quibbles a reader might have with Barkin's treatment of particular authors or issues, his overall aim is a praiseworthy one, especially since it has implications far beyond realism and constructivism. Theory as the elaboration of a core concept, leading to scholarship as a combination of theories appropriate for the task at hand, makes for a far more dynamic field of research than the hoary old “interparadigm debate” ever did. The danger of any sharp definition of a core concept, however, is that the definition might in time become a hindrance to innovation rather than warranting opportunities for innovation—not all constructivists, for instance, are likely to agree with Barkin's particular way of cashing out intersubjectivity via Giddensian agent-structure co-constitution (although this sets up the parallel with Carr's dialectical approach nicely; the fit with Morgenthau's approach is less clear, however) and may in consequence reject the outreach to realism. The cure, perhaps, is to recommend that multiple articulations of the core concept of “realism” or “constructivism” should simultaneously thrive in the field, linked together by what Wittgenstein would have called “family resemblances” rather than by firm logical relationships. Maybe what we need is not just one realist constructivism, but a variety of realisms and constructivisms. And this possibility, perhaps, is the most important element of the new conceptual geography that Barkin proposes: its open-ended character.
