Mr. Umarov emerged from the ruins of Chechnya’s separatist movement, which the Russian government under President Vladimir V. Putin largely defeated. Chechnya itself remains comparatively stable under a regional leader embraced by the Kremlin, Ramzan Kadyrov, who has been accused of ruling through repression and abuse.
Mr. Umarov’s group, which ostensibly aims to create an independent emirate that would unite Russia’s southern Muslim republics, claimed responsibility for ordering two separate suicide bombings on Moscow’s subway in 2010 and an attack at Domodedovo Airport in Moscow in 2011.
Mr. Umarov himself is believed to operate in remote redoubts in the Caucasus, but his whereabouts and his influence over other Islamic militants in the region remain unclear. The International Crisis Group’s recent report outlined a raft of issues that have contributed to Islamic radicalization and violence in the Caucasus, including not only separatist aspirations but also social and economic issues and federal policies.
“Unresolved disputes over territory, administrative boundaries, land and resources are important root causes of the violence, along with ethnic and religious tensions, the state’s incapacity to ensure fair political representation, rule of law, governance and economic growth,” the organization’s report said. “The region’s internal fragmentation and insufficient integration with the rest of the Russian Federation contribute to the political and social alienation of its residents.”