Quantitative analysis of IS thought leader discourse is used to examine the extent to which the IS narrative has changed throughout its history, and the degree to which it has been similar to the rhetoric of other extremist organizations. The IS narrative has remained remarkably stable, indicating an ideological commitment to the narrative by its propagandists. Furthermore, the narrative has worked well for IS as a recruiting and inspirational tool. Therefore, their core narrative is predicted to remain stable, despite future manifestations of the organization. This stability has implications for how the narrative can be countered and the need for credible allies in that effort.