Theorizing Medieval Geopolitics: War and World Order in the Age of the Crusades by Andrew A. Latham (Routledge, 2012) offers a constructivist interpretation of late-medieval European states and warfare. Latham describes his approach as offering an “explanation-what” or “property” theory rather than an “explanation-why” or causal theory. He is interested in clarifying the nature of the medieval “corporate-sovereign state” and the ways in which medieval European societies conceived of and legitimized war. Rather than studying the late-medieval period merely as a staging ground for the development of the modern state, as Hendrik Spruyt does in his interesting book The Sovereign State and Its Competitors, Latham explores the logic internal to the late-medieval system, perceiving the transition from high-medieval feudalism to early-modern absolutism as a gradual one. (He therefore rejects what he calls “the Westphalian rupture” and explicitly endorses both the stateness and non-feudality of pre-Westphalian polities, whether city-states, empires, or kingdoms.)
Constructivism in international relations refers to a broad research paradigm emphasizing the roles of shared international culture, ideas, and values in constraining state actors. It rejects both the “power politics” theorizing of neorealism and the materialism of Marxism. Of course, in one sense the late-medieval period is a “most likely” case for constructivism, as one could hardly deny the role of ideas in buttressing the power of the Catholic Church or provoking the Crusades. But apparently some have tried. Latham successfully shows that realist views prioritizing interests over ideology in explaining the Crusades (e.g., opportunities for looting) are inconsistent with current historical knowledge.
At other points, though, Latham’s obdurate refusal to consider the role of interests annoyed me. In explaining why the medieval kingdom came to prevail over the city-state, the principality, the bishopric, and the city-league, his account boils down to the claim that medieval political philosophy viewed the kingdom as “more legitimate” (90-91). Technological change plays no role in the explanation, and power politics is only begrudgingly and indirectly acknowledged (96).
Latham could also be clearer about the role that his ontology of war can play in general causal theories of international relations. Defining war as an “institution” composed of “deeply embedded intersubjective beliefs” (48) does nothing to bridge the distance between this kind of project and rationalist approaches to war. Why aren’t “norms” (or if one prefers, “deeply embedded intersubjective beliefs”) best thought of as variables in a utility function? (Realists would still not be happy with this, of course.)
The first 50 or so pages of the book bog down heavily in the IR literature. For someone like me largely uninterested in the paradigm bun-fights, the more interesting part of the book comes later. I learned something about the demise of feudalism (it was remarkably early, 13th century at the latest) and something about how Thomist and other late-medieval political philosophy differed from the prior Augustinian tradition (more optimistic about the state’s ability to promote the common good). Medieval historians are unlikely to find much new here, but for political scientists, Latham’s book does a service in synthesizing the up-to-date historiographic literature on the diplomacy and warfare of the period.