The article describes the United States - China rivalry and China’s Belt and Road Initiative (BRI) through a fine-grained review of primary materials such as major US policy documents and speeches by and media interviews with key American foreign policy decisionmakers, as well as the selective use of secondary materials such as think tank studies and articles in scholarly publications. It shows that the BRI has fueled the bilateral rivalry since its birth in 2013 and that the rivalry, in turn, has affected US views about the BRI. Under President Barack Obama, the US took a muted stance towards the BRI, expressing modestly cooperative sentiments regarding it. In contrast, under President Donald Trump, Washington’s posture towards the BRI dramatically changed with his administration frequently denigrating the BRI, raising it in major security and foreign policy documents, initiating competing development schemes such as the BUILD Act, and building closer cooperation with allies against China’s venture. Despite its angst about the BRI, however, the Trump administration never launched any large-scale countermeasures. This article contributes to clarifying the situation by correcting some factual errors in past analyses and updating the general understanding about the Trump administration’s response. It systematically contemplates how internal and external economic, political, and ideational factors affected the Obama and Trump administration’s responses to the BRI, demonstrating that such factors shaped or shifted US policy or bounded its form and intensity. These factors, being similar to those stressed by neoclassical realists who emphasize the role of leaders as interpreters within limits of the external environment and responders to it subject to various domestic constraints, provide a foundation which is used to speculate about the US’s probable response to the BRI under President Joseph Biden, Jr.