Abstract: Role theory provides a vital analytical framework for understanding national diplomatic behaviors and policies. When a state's self-perceived role perception and practices clash with external role expectations in the international system, it may face external pressures arising from this. To achieve stable national role and gain international recognition, states often use role transition as a method for foreign policy adjustment. Japan's diplomatic practice in “human security” reflects multiple roles, which evolve due to internal and external role expectations amid shifting international environment and domestic societal development. The national role has followed a progressive trajectory from a norm advocate, development aid provider, and “peacebuilder” to a values-driven diplomacy practitioner, aid-for-interest seeker, and comprehensive security pursuer. Facing the relative decline in economic strength, Japan is attempting to expand strategic space through “human security”, aiming to construct broader international cooperation frameworks to support its strategic objective of attaining “normal state” status.

Key words: human security, Japanese diplomacy, development aid, role theory