Through bilateral treaties between Moscow, Ankara, Tehran and Kabul, revolutionary diplomacy shaped the ‘Northern Tier’ of the Middle East in the early 1920s. This article argues that the infamous Young Turk leaders, though in exile after the First World War, remained at the centre of a significant moment in transnational revolutionary diplomacy in Eurasia. Based on a hitherto underutilised collection of published and unpublished private papers in juxtaposition with other archival sources, this article illustrates the working of a dual process of internationalism. While campaigning for Muslim internationalism, the Young Turk leaders were able to partake in international politics, but ironically reduced their own legitimacy and capacity as non-state actors by championing revolutionary bilateralism between Turkey, Iran, Afghanistan and Soviet Russia.