A conventional starting-point of international relations scholarship is the division of the world's populated territory into independent political communities, or states, and the distinctive issues that involves: national security, war, intervention, alliances, trade, aid, refugees, and so forth. We could not get very far in trying to make sense of such issues without an underlying assumption about territorial limits of specified normative significance which mark the divisions between independent states: international boundaries. For the past several centuries such divisions have characterized an originally European and now a global international society. It is thus remarkable that state borders are usually taken for granted by international relations scholars. 1 They are a point of departure but they are not a subject of inquiry. My aim in this chapter is to sketch a classical approach to the study of international boundaries. I shall confine myself to three questions. What is the character and modus operandi of international boundaries? How are they determined and changed? Can the current practice of endorsing inherited and existing borders be justified?
The familiar lines on the political map of the world readily imprint themselves on our minds and give rise to a fixed mental image of world politics. They can easily be regarded as natural or inherent divisions of some kind. Yet it is obvious that neither borders nor the states defined by them are given in the nature of things: the political map could be different and in the past it has been different. International boundaries are political constructs. They remain political constructs even where they follow physical landforms or where they accompany ethnic or religious or linguistic or cultural divisions. They may be aligned with