The literature on international arbitration has been fragmented, because the practice of international arbitration has, for some time, also been fragmented. In the space between the well-established (but relatively isolated) communities of legal practice that operate in the ‘public-law’ arbitration of interstate disputes and the ‘private-law’ arbitration of international business disputes, there has been the relatively recent development of ‘mixed’ investment arbitration that has caused those two legal communities to move closer to one another, and to overlap. This has enabled the consideration of international arbitration and its legal framework as a unified subject of inquiry. In this paper, the author explores the commonalities that this perspective highlights in terms of “sources.”

In the first part of the paper, the author considers the development of the different worlds of international arbitration since the late nineteenth century by dwelling on elements that are often overlooked when the recent story of international arbitration is told. In the second part of the paper the author provides an overview of the potential features, and the hurdles that stand in the way, of a unified representation of international arbitration.