During the past decade there has been a resurgence of interest in the concept of recognition in international theory. Once the narrow concern of social theorists, the concept of recognition is nowadays invoked in at least three different senses in order to explain three different things. First, it is commonly used to explain how states and their identities are shaped by interaction, and how the modern international system has emerged as a cumulated consequence of such patterns of interaction. In this context, the concept of recognition is used to explain how states are individuated and differentiated from each other, how the international system thereby becomes stratified along status lines, as well as why conflicts over status are possible or even inevitable. Second, although the concept of recognition has long enjoyed wide currency within international legal theory, where it is used to account for what makes states legal persons and equal members of international society, recent scholarship has done much to complicate this view by pointing out how practices of inclusion often have gone hand in hand with practices of exclusion, and how this has led to an informal stratification of international society. Third, the concept has most recently been invoked to suggest how the undesirable consequences of international anarchy can be mitigated or even avoided through mutual recognition between political communities.