Although the study of ‘the state’ as a policy actor has diminished in the shift from international to global health, states remain critical to the creation and implementation of policies to improve health. However, assessments and understanding of why states engage (their motives), how states engage (their approaches), and where states engage (which fora and policy processes) remain limited. This study analyses the role of the state, with case studies of Japan and Indonesia, in terms of why, how and where they engage in global health, focusing on the process to conceptualize the post-2015 Sustainable Development Goal for health (SDG3). Constructivism provides the conceptual foundation to understand why states engaged, and Barnett and Duvall’s power framework is applied to understand how and where states engaged. The thesis demonstrates that states construct their engagement in global health as part of their foreign policy efforts; both case studies highlight how critical the construction of a narrative, and the process to do so, is to motivate and shape state engagement. This has implications for how and where states engage. Both Japan and Indonesia state actors engaged in the post-2015 process exerting institutional, productive and structural power to advance domestic political interests. Most notably, Japan’s government exerted institutional power leveraging its relationships within both the World Bank and the World Health Organisation; Indonesia’s government exerted structural power with its President co-chairing the UN Secretary-General’s High-Level Panel. While power frameworks do not explain all global health policymaking outcomes, they do help illuminate how and where actors engage and exert power in policymaking processes. Indeed, applying analytical frameworks focused on power in global health helps deepen understanding and insight into how and where different state (and non-state actors) coordinate, collaborate and contest policy priorities.