We report on the development and use of a course-long, online simulation in a recent, upper-level undergraduate course on the International Relations of COVID-19. We demonstrate how to conduct a simulation in an entirely online environment by including a description of our processes and logistical advice, guidance, and specific examples. This simulation format can be easily translated to fit varying durations, issue areas, and in-person formats. Our students reported that the simulation was a rewarding and thought-provoking experience, as they were offered a front-seat view to the inherent substantive and logistical challenges of international negotiation about an ongoing international crisis in real time.