About one in six Asian Americans have fallen victim to anti-Asian racism during the COVID-19 pandemic [J. Lee, K. Ramakrishnan, aapidata.com/blog/discrimination-survey-2022/]. By examining anti-Asian racism in the United States primarily as a domestic issue, most prior studies have overlooked the connections between shifting US-China relations and Americans’ prejudices against the Chinese in China and, by extension, East Asian Americans. This study investigates the patterns and perceptual bases of nationality-based prejudices against Chinese amid the COVID-19 pandemic in the United States. Our nationally representative online survey experiment reveals that Americans assess a hypothetical Chinese person in China as inferior in multiple social and psychological characteristics to an otherwise identical Japanese person in Japan or East Asian American. Furthermore, subjects who perceive China as more threatening to America’s national interests assess Chinese more negatively, especially in terms of trustworthiness and morality, suggesting that perceived China threats propel Americans’ negative stereotypes about Chinese. A contextual analysis further indicates that counties with a higher share of Trump voters in 2016 tend to perceive all East Asian–origin groups similarly as a racial outgroup. By contrast, residents in predominantly Democrat-voting counties tend to perceive Chinese in China more negatively relative to Asian Americans, despite broadly viewing East Asians more favorably. Overall, this study underscores the often-overlooked relationships between the prevailing anti-Asian sentiments in the United States and the US-China geopolitical tensions and America’s domestic political polarization.