The Belt and Road Initiative (BRI), ten years since it began, has become China’s guiding foreign engagement and economic governance principle in the Xi Jinping era. However, questions remain -- with regards to their implementation, why do megaprojects encounter such divergent responses -- with some gaining local support while others causing local grievances? This paper addresses these questions by conducting sub-national level analysis and by applying the Advocacy Coalition Framework (ACF) in tracing the rise and fall of economic-centered coalitions in the Kenyan Standard Gauge Railway project, one of the most controversial and influential China-financed megaprojects of the BRI. The paper is part of a book project on the impact of Chinese-led infrastructure megaprojects in the Global South. Our research is based on fieldwork in China and Kenya between 2015 and 2023, and we conducted over 300 surveys and interviews with stakeholders involved with BRI project development and community-based project impact assessment. Our findings suggest that the BRI developed its current form from China’s domestic experience driven by economic interests, which laid the foundation for economic-centered coalitions that contributed to progress during project construction. Yet. such coalitions fluctuated with interest redistribution, which changed project outcomes, and led to future uncertainties in project development and Initiative success. The research project fills the gap in existing literature by providing a sub-national perspective on the impact of Chinese overseas engagement and provides a new pathway for assessing China’s growing sphere of influence.