As authoritarian regimes increasingly adapt domestic tools for outward-facing propaganda, they often target diasporas for internal stability and foreign policy reasons. We develop a theory of diaspora-targeted propaganda in which autocratic governments use wedge narratives – identity-based and political – to divide diaspora from host countries, by framing racial discrimination and violence as targeting the diaspora and alternative political systems as inferior. We test our theory in the salient case of China. We measure propaganda framing with an unsupervised machine learning methodology, word embeddings, and apply it to data scraped from a prominent social media platform, WeChat. Consistent with our expectations, Chinese government accounts amplify coverage of anti-Asian racism and hate crimes in the United States, and portray democracies as chaotic and corrupt. These findings suggest that diaspora-targeted propaganda strategies can undermine the functioning of democratic and multicultural societies as part of an authoritarian foreign influence toolkit.