The term “security” has many more dimensions in the post-9/11 world than it had during the Cold War. Threats may come from different sources, at different speeds, and have different targets. All the actors involved in the provision of security from a specific type of threat create a network—not just states or states in intergovernmental organizations, but all the actors in the “ecosystem." If we look at the relationships among these actors using network analysis, we should be able to map the structure of the entire network. Contrary to the assumptions in most International Relations literature, networks can be centralized (as in hierarchical states) or not, as in markets. The networks transnational actors have created to meet different threats exhibit different structures, from dense and highly centralized to diffuse and dispersed. The network’s structure may thus have a positive or negative effect on the provision of security, depending on the type of threat that is to be met.