The role of the US in the 1964 coup in Brazil is controversial. When did US policymakers decide to support the coup conspirators, and why? This article reviews some recent works on the 1964 coup and makes two arguments. First, recently declassified documents show that the US joined the coup conspiracy only in 1963 not, as some claim, in 1961 or 1962. Second, many scholars do not explain the actions of US policymakers, or see their decisions as the inevitable consequence of US imperialism. This article argues that shifts in US domestic politics during the Cold War, as well as the pattern of post‐war foreign policy in Latin America, help explain US support for the coup.