After the fall of the Islamic State’s self-declared Caliphate in Syria and Iraq, understanding how the Salafi-jihadist environments in the West mobilize in new ways has become urgent. This study is based on unique hard-to-reach data from qualitative interviews with returned Swedish ISIS fighters, previous members of the Swedish Salafi-jihadist environment, friends and acquaintances of persons engaged in the Swedish Salafi-jihadist environment, and a former Swedish jihadist recruiter. It explores post-Caliphate mobilization in terms of recruiting new members, keeping old members, and sustaining support from other radicals who are not active members of the Salafi-jihadist environment. Five distinct themes emerged from the interviews that reflect changing “push” and “pull” factors, which in different ways make mobilization in the post-Caliphate period challenging: competition from criminal gangs, increasing fuzziness of the environment, limited ability of external events to mobilize both new and old members, variation in the ease of leaving the Salafi-jihadist environment, and lack of new heroic mobilization narratives. The study concludes that, despite continuing problems in so-called radicalization hubs in Sweden, IS and other jihadist groups now have difficulty mobilizing both old and new members. In particular, changes in pull factors suggest that the current mobilization dynamics point to an environment that is facing challenges.