<p>Are states willing to honor their international obligations with private parties as much as they do with other states? We explore this question by analyzing arbitral awards administered under the auspices of the Permanent Court of Arbitration (PCA) between 1902 and 2020. The PCA began as an institution to address inter-state disputes, went dormant during much of the twentieth century, and resurged as a major forum for investor-state arbitrations in the twenty-first century. We argue that three mechanisms—the nature of consent, the parties’ ability to forum-shop/shape the procedures, and the legitimacy of proceedings—make states more likely to comply with international obligations when dealing with other states. The empirical evidence suggests that, even when governments are likely to honor obligations towards private parties, they comply significantly faster when dealing with other states.</p>