When states claim each other’s territory, they use detailed legal arguments to convince each other and third-party actors that international law favors them. Under what conditions do legal claims shape and limit the actions of disputants and third-party actors in a territorial dispute? When and why do third-party actors get involved in territorial disputes to enforce international law? In my dissertation project, I argue that legalized territorial claims serve as a focal point that informs and coordinates actors’ behavior. In the first part of the dissertation, I formally model the bilateral interaction between disputants(a challenger and a target) with a cost of punishment as a function of the strength of the challenger’s legal claim for using force. Moving from the model, I argue that an increase in the challenger’s legal claims emboldens it to act demandingly and increases the likelihood of using force. I test this hypothesis by using the claims and legality dataset of Huth, Croco, and Appel (2011). In the second part, I argue that third-party actors are more likely to intervene in disputes with the intent to uphold international law and punish the challenger for using force as the challenger’s legal claim gets weaker. I test this claim by using a large-N qualitative analysis of the sample of disputes in which force is used and third parties intervene. With this study, I aim to contribute to the literature on territorial disputes by creating a cohesive and comprehensive theory and a novel qualitative dataset on legality and territorial disputes.

​

​​