November/December 2006 Historically Speaking 11 International Relations Theory and Diplomatic History THE ROLE OF THEORYIN HISTORICAL INQUIRY HAS BEEN much debated. Comfortable with the intuitive instincts honed by long hours spent with primary documentation, many historiansdo theirbestto avoidtheory. Butstrictavoidance of theory is impossible. British historianMary Fulbrook,forexample, arguedin thesepages back in November 2003 that "all historicalaccounts are inevitably theoretical . " The issue, rather, is how bestto utilise theory in historicalanalysis. In no subfield is this more important than in diplomatic history, which has a large body of international rehtions theoryfrom which to draw. Distinguished UCLA diplomatic historian Marc Trachtenberg explores these matters in his The Craft of International History: A Guide to Method (Princeton University Press, 2006). In the essayprinted below, Trachtenberg argues that both diplomatic historians and internationalrelations theorists couldprofitfrom talking more to each other. We askedagroup ofprominentinternationalrektionsscholarsandhistoriansto respondto Trachtenberg, afterwhich he supplies a rejoinder. Theory and Diplomatic History Marc Trachtenberg Ahistorical interpretation has to have a conceptual core. The facts—and this is a point that the distinguished philosopher of science N.R. Hanson made with great force many years ago—never really just "speak for themselves." The historian thus has to make them "speak" by drawing on a kind of theory—by drawing, that is, on a certain sense for how things work. But what does this mean in practice? What role does theory in that broad sense play in actual historical work? In very general terms, the answer is simple : theory is above all an instrument of analysis , and, depending on what that analysis reveals, it can also serve as the basis for interpretation . But that point is very general, so let me explain what I mean by giving a specific example . It relates to a passage in an article written over seventy-five years ago by the French historian Elie Halévy, perhaps the finest historian of his generation. Halévy in that article—it was actually one of the Rhodes lectures he gave at Oxford in 1929—summed up the origins of the First World War in a single but quite remarkable paragraph. By 1914, he wrote, Austria's leaders had come to believe that the problem of Slav nationalism could be dealt with only if Serbia were crushed militarily. "But everyone knew, who chose to know, that, whenever Austria declared war upon Serbia, Pan-Slavist sentiment would become too strong for any Russian government to resist its pressure," and "everyone knew, who chose to know, that whenever Russia gave so much as a sign of declaring war upon Austria, PanGerman feelings would compel the German government to enter the lists in its turn." "It was likewise common knowledge," he said, "that Germany , whenever she declared war upon Russia, was resolved not to tolerate the existence in the west of "The Prussian Bully invades an inoffensive Neutral Country." Punch, August 12, 1914. an army that was after all the second best army in Europe; that she would first march upon Paris and annihilate France as a military power, before rushing back to the east, and settling matters with Russia ." It was also clear that in order to implement that plan, the German army felt it would have to march through Belgium. But "everybody understood that if ever the Belgian coast and the northern coast of France were to fall under the domination of Germany , Great Britain, feelingher prestige and her security in danger, would enter the war on the side of Belgium and France." What all this meant was that by 1914 war had become virtually inevitable: "everyone knew, who wished to know, not only that a European war was imminent , but what the general shape of the war would be."1 Halévy was a truly great historian, and it is amazing how much he was able to pack into that one paragraph. A mere decade after the fighting had ended, he was able to analyze the coming of the war with Olympian detachment . He had a sense of tragedy. Events unfolded in accordance with a certain inexorable logic, and it was the historian's job not to blame one side or the other for the war, but simply to show what that...