Since Chinese leader Xi Jinping launched the Global Security Initiative (GSI) in April 2022, it has been used in China's efforts to expand its international security role and reshape global order. Drawing on field research and discussions with regional policymakers and experts, this report looks at Beijing's progress in implementing and operationalizing the GSI in the priority regions of mainland Southeast Asia and Central Asia, and it examines key policy implications, explaining why the initiative warrants greater attention on the part of the US policy community.