Recent evidence suggests that historical boundary precedents play a central role in the outbreak, character, and long-term consequences of territorial disputes. The institutional theory of borders holds promise in explaining why leaders find old borders to be attractive as new borders. However, the mechanisms that link historical precedents to territorial claims and their consequences are not fully specified in the extant literature. I argue that there are three key arguments that can explain why boundary precedents are associated with subsequent disputes: (...) ease of justification, perpetual conflict over territories of particular value, and persistent coordination around old borders. I argue that the coordination mechanism is essential to understanding the connections between historical boundary precedents and territorial disputes. (shrink)