In a seminal article, Robert Putnam (1988) used the metaphor of “two-level games” to describe how government officials conduct foreign policy by simultaneously engaging in negotiations at two levels: domestic and international. This idea of foreign policy decision-makers as brokers along the domestic–foreign (or international) frontier has since gained significant ground in the academic literature. It has provided new avenues to explore the links between foreign policy analysis and international relations. Studies looking more closely at both the domestic and the international level subsequently acknowledged that these levels are themselves made up of different levels (Piattoni 2010; Woolcock 2011; Cottier and Hertig 2003). Domestically, there are a number of governmental (national and subnational) and nongovernmental actors that interact among themselves (see Chapter 14). Internationally, negotiations take place at bilateral, regional, multilateral and other levels. Not only do these actors operate at multiple levels at the same time, they also use one level to influence the other(s).