It is often assumed that Indo-Iranian cultural entanglements disappeared by the early twentieth century because of the rise of imperialism and colonialism, exclusionary forms of nationalism, and the accompanying loss of certain linguistic competencies. This article calls into question the supposed disappearance of exchange between Iran and India in linguistic, literary, and religious realms. Instead, it posits that earlier sets of debates between Iranian and Indian authors, particularly on the status of the Persian language, were now inflected through nationalism, imperialism, and cosmopolitanism. It traces how these new cultural articulations were often the outcome of crossings among Iran, India, and Europe for educational, journalistic, and missionary purposes. Through these crossings, cosmopolitan understandings of language, religion, and politics, albeit with their own hierarchies and exclusions, often coexisted paradoxically side by side with nationalism. Shared Indo-Iranian religious connections, either through Zoroastrianism or Islam, became grounds for new modes of imagining transnational solidarities, while viewing Persian as a beleaguered Asian lingua franca became a way of challenging the imperial hegemony of the English language.