Dale Copeland’s Economic Interdependence and War is an ambitious book that should receive close attention from both international-relations theorists and diplomatic historians. The author’s main objective is to offer an alternative explanation of the relationship between commerce and international conflict, one that challenges both liberal and realist theories. In his view, liberals are correct to believe that increasing trade and investment flows can enhance the prospects for peace, but realists also have solid grounds for believing that increased economic interdependence can lead to conflict and war. It is because both theories are plausible, Copeland argues, that it is necessary to consider an additional variable that he defines as “a state’s expectations of the future trade and investment environment” (2). When states have positive expectations about the future trade and investment environment, they are unlikely to resort to war. But if a state has negative expectations about the future, it is going to be more willing to consider war as an attractive policy option. It is this argument that Copeland tests against the historical evidence of great-power conflict from 1790-1991 and also applies to the future of U.S.-Chinese relations in the twenty-first century.