This research report measures changes in China's public diplomacy after a May 2021 collective study session of the Chinese Communist Party Politburo. The session examined the country's global communications strategy and fuelled speculation about what might change in China's external communications, particularly with regard to its “wolf warrior” diplomats. Combining hand-coding and quantitative text analysis, we develop and validate a measure of “wolf warrior diplomacy” rhetoric and apply it to over 200,000 tweets from nearly 200 institutional, media and diplomatic Twitter accounts. Using a difference-in-difference research design, we evaluate if the session led to a noticeable change in the tweets of diplomats based in OECD countries. After the announcement, PRC diplomats in the OECD moderated their tweets in comparison to non-OECD diplomats, but we do not detect a major re-orientation of PRC communication strategies. These findings have relevance for scholars of Chinese foreign policy, nationalism and public diplomacy.