Democracy, War and Expansion through Historical Lenses

This article examines various implications of democratic peace theory in both the contemporary era and in Greece during the Peloponnesian War era. It considers the evidence for various hypotheses in both con-texts, to understand why those hypotheses — especially those concern-ing institutions — find much better support in the contemporary era. It also addresses the causes and possible consequences of expansionist policies, including hypotheses that democracies are more effective war-fighters and thus better able to pursue successful expansion by military means. KEY WORDS ♦ democratic peace ♦ empire ♦ Kant ♦ Thucydides ♦ war This article addresses some puzzles about the contemporary democratic peace, stimulated in part by two great classics of International Relations, Thucydides ’ History of the Peloponnesian War, and Immanuel Kant’s Perpetual Peace. In very different ways, both these voices from the past can tell us important things about the present. When linked with contemporary social science research they can illuminate important influences on peace, war, and expansion both in the interstate system of classical Greece and in the contemporary world system. The analysis begins with some general comments on what contemporary theory and evidence about the democratic peace (DP) most centrally claim, and then discusses how they apply to two questions that must be kept sep-arate: Are democracies peaceful in general? Or are they peaceful only toward one another? In discussing both these questions I consider how well the reasoning and evidence for each apply to both the ancient and modern periods