["Journal of Agricultural Economics, EarlyView. ", "\nABSTRACT\nThe US–China trade war has profoundly reshaped global agricultural markets, yet the consequences of protectionist measures for domestic public attitudes—particularly within collectivist societies like China—have been underexplored. This study investigates how Chinese citizens perceive retaliatory tariffs on US agricultural products and explores how awareness of economic self‐interest shapes their support for such policies. We develop a simple theoretical model showing that trade policy attitudes are shaped by both social values and economic beliefs, with the influence of new information moderated by trust and cognitive capacity. The model predicts that information interventions can recalibrate beliefs towards actual economic interests, with effects varying by information credibility and individual human capital. Employing a randomised controlled trial in 2023, we demonstrate that backing for trade protection in China is robustly associated with collectivist values. Individuals demonstrate a strong propensity of alignment with government positions over economic self‐interests. However, when people learn about how tariffs will personally affect their household costs, they become less supportive of trade protection because they revise their expectations about economic consequences. Notably, the efficacy of these interventions depends critically on the respondents' trust in information and their level of human capital. Our findings offer new insights into the dynamics of public opinion formation in contexts where information flows are state‐mediated, with direct implications for the design of agricultural and trade policy communication strategies.\n"]