Recent research on factional conflicts during the initial years of the Cultural Revolution has revealed the deep involvement of the armed forces in factional battles among rebel forces and the striking extent to which regional army units themselves were divided into factions. The origins of these intra-army splits have received little attention. In a detailed examination of the course of the army’s involvement in the severe and prolonged factional infighting in the northern Jiangsu prefecture of Xuzhou, we trace intra-army splits to decisions made by local commanders in shifting circumstances, and their efforts to defend their initial actions after central policies changed, threatening to turn them into scapegoats. Pressures from above to force recalcitrant officers into line served to split local military commands and intensify alliances between opposed army and civilian factions. The complex organizational structure of domestic military commands exacerbated these locally generated divisions and made them more difficult to resolve. Xuzhou is an extreme case of a pattern that was likely repeated across hundreds of regions during this chaotic period, threatening the integrity of China’s armed forces and influencing Mao’s ultimate decision to curtail this phase of the Cultural Revolution.