This dissertation examines the emergence of Sino-Indian friendship in post-war India and China, the Asianism at the heart of this discourse, and the grassroots' reception and translation of the ensuing imaginations of 'New Asia'. Justifying their countries' relationship through their shared 'Asianness', the advocates of Sino-Indian friendship responded to the defining phenomena of their time: the Cold War and decolonization. As nuclear annihilation threatened the prospects of their postcolonial futures, different groups across transnational networks in both countries used 'Asia' and its accompanying vision of affective ties and anti-imperialism to yoke the fate of Sino-Indian friendship to the fate of politics at home and vice-versa. By focusing on the way these different 'publics' confronted the Cold War via alternative visions of politics and the international system, this dissertation also answers broader questions about the blurred lines between socialist/nonsocialist and official/unofficial discourses of anti-imperialist solidarity in the postcolonial era. I will begin with a study of the India-China Friendship Association and the China-India Friendship Association's advocacy of anti-imperialist nationalism, peaceful co-existence, and affective international relations as 'Asian' values. The dissertation will then proceed to show how grassroots organizations – including workers, feminists, peace-activists, land reformers, and Buddhists – imagined 'Asia' in a way that spoke to their own desires and anxieties. The dissertation examines how the values of Sino-Indian friendship then spread outwards throughout transnational networks in the region and transformed this Asianism into a new political universal. By utilizing neglected sources and archives, this dissertation will complicate our understandings of Sino-Indian relations in the 1950s and excavate the radicalism that was at the heart of the postcolonial response to the Cold War.