A significant intellectual advance in the discussion of democratic peace theory and the future of liberal ideas and institutions. After a century dominated by the struggle between liberal societies and their illiberal communist and fascist opponents, the importance of liberal ideology in international relations can hardly be doubted. Whether liberal politics and liberal economics will dominate the twenty-first century is one of the most important questions facing policymakers as they peer into their murky crystal balls.
Mandelbaum makes a striking contribution to this discussion by broadening the concept of liberal society. Liberal political institutions and liberal economic practices are conventionally used to define a liberal order; Mandelbaum adds liberal security arrangements as a third, equally vital element for this order. Liberal security, in essence, requires among countries a structure of military and political agreements so dense that each member state can be confident about the capacities of the others. In this kind of system, which now exists in western and central Europe, nations are confident that their neighbors are unable to overturn the existing strategic balance. Such an order, Mandelbaum argues, is solid and stable enough to give states every security assurance that hard-nosed realists might demand. Liberal security policy -- the origins of which Mandelbaum traces to Woodrow Wilson's program at the Versailles Conference -- adds an important dimension to the arguments for democratic peace. Mandelbaum is also to be commended for an epistemological modesty too rare in his field. For offensive realists, war is inevitable because it is hard-wired into the nature of the international system. Liberals have similarly sought to develop rigorous chains of logic to show the contrary. More effectively, Mandelbaum concludes that the twenty-first century will very likely see the continuing advance of liberal order. His reasoning is open to dispute at many points, but even those who disagree with his analysis will find much to admire in its clarity, consistency, and comprehensiveness.