Network analyses of global and regional arms flows (including small arms and light weapons, major conventional weapons, and weapons of mass destruction) and related international insecurity and criminality have so far been limited. Yet the literature contains hypotheses that could be explored or tested using network analysis. This chapter discusses supply and demand effects, structural tradeoffs between security and efficiency, pressures to become more or less centralized, and the effects of geography and other network layers. It concludes by reviewing existing data sets and analyses and gauges the potential for network analysis to inform the study of arms transfer networks. Given the general import of these networks for both security studies and policy, there should be a renaissance in the study of arms supply and proliferation networks.