The world and the nation are in the midst of fantastic and bewildering social, economic, and political changes. Structural analysis is indispensable for documenting and explaining these upheavals. The network perspective on power relations among social actors, traced in the preceding chapters, can contribute important insights at every level of analysis. Table 8.1 summarizes these basic components in a rough hierarchy from the individual to the international system of nation states. Without recapitulating the table in detail, we can appreciate the vast range of influence and domination relations that appear in many guises. As exchanges of informative communications, influence relations span the dyadic persuasions among friends to the cultural imperialism of modern science and business. Domination relations, based on positive and negative resource sanctions, likewise range from the gift giving and mutual supports that generate reciprocal obligations among persons to the coercive trade and military interventions of nations. Comprehending the complexities of these manifold power dynamics within any single type of social formation is fraught with the difficult tasks of conceptualization, measurement, and interpretation. Consequently, most network theorists and researchers still confine their efforts to the characteristic nodes and ties within one level of analysis. Yet the central challenge for the coming years will be to extend the structural approach to networks crossing multiple levels, showing how they simultaneously condition and constrain one another.