Computational diplomacy, the application of digital and computational methods to the study and practice of international negotiations, presents unique challenges compared to most other fields in the computational humanities and social sciences. Among them are the necessity of responsiveness when handling crises, the need to anticipate and respond to adversarial behavior, or the need for secrecy in dealing with sensitive information. In this paper, we propose an agenda to address these challenges, and evaluate the feasibility of the various tasks that could be assigned to computational diplomacy. While most analysis tools seem almost ready to use, the availability and reliability of diplomacy-related data remains a major concern.