This book is a collection of Russet's earlier work on the democratic peace, the finding that no two democracy have ever gone to war with one another, with an emphasis on those works that expand the empirical realm of testing. The first two chapters essentially summarize the literature on the democratic peace (up until 1993) explaining both its empirical roots and the theoretical arguments. After summarizing the normative and structural explanations, Russett (with William Antholis) attempts to discover if the democratic peace extended to Ancient Greece. Finding only minor support Russett hypothesizes that peace needs not only the simple institutions of democracy, but also the perception, by other democracies, of the type of regime. Without the mutual recognition the norms and institutions democracy may fail to prevent conflict. Russett (with Zeev Maoz) then applies the democratic peace to the post World War II era and finds that joint democracy does in fact promote peace. The last empirical study in the book deals with non-industrial societies (done with Carol and Melvin Ember). While it remains difficult to gain a strong relationship, they do find that participation, joint participatory societies, matters in reducing conflict. In general, this book is a good summary of Russett's early work on the democratic peace and provides some interesting tests as the theory is applied to non-nation-state eras. For those new to this literature it is a good place to start.