Since 2018, US foreign policy elites have portrayed China as the gravest threat to their country. Why was China predominantly cast as an ideological threat, even though other discursive formulations, such as a geopolitical threat, were plausible and available? Existing major IR theories on threat perpcetions struggle to address these questions. In this article, we draw from rhetoric and public legitimation scholarship to argue that the mobilization of adjacent policy debates was key to mainstream the representation of China as an ideological threat. By mobilizing debates on Russia and the soft power and sharp power concepts, a minority view in US foreign policy with a longstanding ambition to get tough on China established a seemingly natural link between liberal internationalism and an ideologically threatening China. Liberal foreign policy elites who originally opposed a realpolitik view of China could now subsume a geopolitical threat into an ideological one reminiscent of US-Soviet Cold War rivalry. This constituted a necessary catalyst to align most foreign policy elites to understand China as the gravest threat to the United States, at a time when China's capabilities and behaviour, coupled with a deep sense of insecurity regarding America's place in the world, provided the necessary backdrop.