"To better understand the renewed fighting between ISS and al-Shabaab, it is important to first look at the history of the rivalry between the two. Starting in 2015, propaganda released by the Islamic State began to focus on encouraging members of al-Shabaab to defect and join its cause. In a piece published in this publication in November 2017,6 this author and researcher Jason Warner identified the earliest known call to al-Shabaab to join the Islamic State’s so-called caliphate as occurring in February 2015, when Islamic State propagandist Hamil al-Bushra penned an article for the Global Front to Support the Islamic State media.7 c
Following the first article, more pieces were released through various outletsd before the Islamic State’s media office for its Iraqi “province” of al-Furat released the first video addressed to Somalia in May 2015.8 Over the course of four days in October 2015, six videos were then released from Syria,9 Iraq,10 Yemen,11 and the Sinai12 attempting to persuade al-Shabaab to join its cause. Two weeks later, a video was then released from Nigeria,13 while in January 2016, another was released from Libya."