Following the First World War, nationalists in several parts of the British empire amplified their calls for greater self-government. Activists in Egypt, India, and Ireland portrayed themselves as representatives of movements for national self-determination. Their opponents countered that religious divisions undermined these groups’ claims to nationhood, making the presence of an outside power necessary to protect minorities. Activists formed networks and positioned themselves as parts of a worldwide anti-imperialist movement. Their opponents used these ties in attempts to portray separatist movements as foreign-inspired and socialist. Irish republicans and their global counterparts also struggled with accusations of sectarianism as they advanced their independence claims. This article examines Irish republicans’ connections with international revolutionaries. The confluence of political and religious identities there and in other parts of the British empire provided a pretext for continued imperial engagement. Partition forced nationalists to adjust to new geographic and demographic realities in their post-independence states.