This paper uses the case of Sino-Southeast Asian relations to gain insights into China’s ability to muster support for its global agenda. The analysis focuses on the regional-global nexus of interstate relations and explores the extent to which the quality of two states’ regional relations influences the likelihood of behavioral alignment in global politics. To this end, we consider a range of potentially influential aspects of Sino- Southeast Asian relations such as the quality of bilateral relations based on recent event data, economic ties and regime similarity as well as measurements of countries’ external alignments and national development levels. We employ a statistical model to search for correlations of these factors with observed trends of voting coincidence in the United Nations General Assembly during the period 1980-2014. We find a strong correlation between the quality of regional bilateral relations and global policy alignment, which indicates that patterns of regional cooperation and conflict impact the trajectory of China’s rise in world affairs.