This Key Concepts pivot discusses the contemporary relevance of the ancient Chinese concept of Tianxia or 'All-Under-Heaven' and argues the case for a new global political philosophy. 'All-under-heaven' is a conceptualization of the world as the composition of three realms: the physical, psychological and political, which places inclusivity and harmony at the heart of a global world view above other considerations, transcending the notion of nation state. In a highly interconnected and globalized world, the idea of Tianxia can offer a new 21^st century vision of international relations and world order, based on a harmonized global organization defined by the all-inclusiveness principle. Promoting the ontology of co-existence and relational rationality hand in hand with rational risk aversion in a globalized world, this pivot makes the case that Tianxia could offer a new vision for contemporary world order, redefining the universality and legitimacy of politics.