In 1924, the government of Afghanistan wrote to the Jam'iyat 'Ulama-yi Hind looking for legal justifications to support Amir Amanullah Khan’s (r. 1919–1929) proposed reforms—particularly those relating to female education. Known for securing Afghanistan’s independence from the British and now recognized as a pioneering modernizer and renegade constitutional monarch, Amanullah introduced a series of reforms during his reign that one scholar has recently characterized as “a burgeoning model of Islamic legal modernism.” Yet the story of Afghanistan’s experiments with Islamic legal modernism are greater and extend beyond the history of a single state. Taking the above claim about Afghanistan seriously, then, this paper offers a close reading of the exchange between Kabul and Delhi to interrogate ideas about Islamic legal reform, Islamic modernity, and inter-Islamic circulations at the time of waning empires and rising nation states. In recent years, there has been a renewed interest in the idea of the Islamic world, Muslim cosmopolitanism, pan-Islamic connections and circulations, and the importance of inter-Islamic intellectual networks that gave shape to modernist ideas in the context of new nation-states and national(ist) reforms. This scholarship not only draws attention to the rich potential of examining cross-cultural and trans-regional connections but also raises questions about the directions in which influences, information, and ideas flowed. Building upon this expanding field of research, this paper focuses on one instance of inter-Islamic exchange from the beginning of the twentieth century. At one level, the exchange between Amanullah’s government in Kabul and Mufti Kifayatullah (d. 1952) in Delhi revolved around the Amir’s proposed reforms for female education and the Indian 'ulama’s ability to provide legal justifications for the government's proposal. At another level, the exchange broached a range of topics from the relationship between Muslims and non-Muslims, to the idea of a global ummah, to questions of Islamic authority in the wake of the Ottoman empire’s collapse. Placing this exchange within the broader context of inter-war international affairs allows it to speak to broader issues of Islam, law, and governance that undergirded the Amir’s approach to reform. In drawing attention to the nature and context of this exchange, I argue that the 'ulama played a key role in supporting “modern” reforms that on the surface appear detached from “tradition.”