With Iraq weakened and a civil war raging in Syria, it’s unclear whether local forces and a U.S.-led international coalition can roll back the self-proclaimed Islamic State.

Boko Haram, the jihadi insurrection associated with some 350,000 deaths since 2009 in northeast Nigeria, was characterized by factions—conflict among which was bloody—though at times they appear to have cooperated tactically. Now, the faction associated with the self-proclaimed Islamic State, the Islamic State in West Africa (ISWA), is claiming to have incorporated the followers of the rival faction led by Abubakar Shekau. (Weeks ago, Shekau died, apparently after committing suicide in a standoff with ISWA.)

The Islamic State in West Africa (ISWA) has announced that it has replaced Abubakar Shekau with Abu Musab al-Barnawi. Abu Musab "takes over all territories that were under Shekau. The immediate replacement of Shekau was a major revenge against the former Boko Haram leader that exhibited ‘highhandedness and ruthlessness’ against humanity in the Northeast." The announcement also included that ISWA had arrested thirty top commanders that were loyal to Shekau.

The Shekau and al-Barnawi factions of Boko Haram continue to evolve and even grow. Changes in leadership and tactics raise questions about the extent of their affiliation with IS and overall stability, but they also indicate that the movement is far from defeated.