Although there has been widespread attention to the apparent rise of a transnational society of cross-border non-state actors alongside the international society of states, transnational society and international society have traditionally been treated as distinctive domains with different institutions. This article, by contrast, aims to transform theorization of world order through its investigation of how actors in transnational society have developed institutions that mirror in notable respects some of the primary institutions of the international society of states such as through serving constitutive and regulative functions. In addition to delineating these institutions of transnational society, the article interrogates the interdependence of these institutions of transnational society and those of international society, as well as their differences and repercussions for world order. The analysis considers how, in conjunction with the contribution of institutions of international society to international order, institutions of transnational society contribute to transnational order. By exploring not only the tensions between but also the complementarities of transnational and interstate institutions, the article both provides a reinterpretation of contemporary world order and helps reveal the potential for its more harmonious operation.

Intermestic security challenges arise when there is concern in a country that a dissatisfied minority relies on transnational bonds with a foreign kin group for support. They result from ethnic and/or ideological affinities translating into foreign support seen as problematic, and they are aggravated when the dissatisfied minority is able to raise territorial claims. This can lead to complications not only in domestic politics, but also in international relations (hence, the term ‘intermestic’). Intermestic challenges can escalate into civil war and other political calamities, but they can also be managed by governments. This article develops a theoretical model and discusses it with regard to China and its Muslim-majority neighbouring countries. To the west of China, transnational bonds of Uyghur Muslims in Xinjiang with co-ethnics and coreligionists in Central Asia, Pakistan, and Afghanistan complicate Chinese relations with those countries. In the southeast, transnational bonds of ethnic Chinese in Indonesia and Malaysia with their ancestral homeland have complicated Indonesian and Malaysian relations with China. While the cases have followed different trajectories, Beijing has managed either challenge rather successfully. The theoretical model developed and the management strategies discussed are likely to be useful in other contexts.