The Supply Side of Security conceptualizes military alliances as contracts for exchanging goods and services. At the international level, the market for these contracts is shaped by how many countries can supply security.

Tongfi Kim identifies the supply of policy concessions and military commitments as the main factors that explain the bargaining power of a state in a potential or existing alliance. Additionally, three variables of a state's domestic politics significantly affect its negotiating power: whether there is strong domestic opposition to the alliance, whether the...