The Sahel has become the epicenter of global terrorism, accounting for half of all terrorism-related fatalities by 2024. Jihadist groups pursuing system-transforming agendas have expanded across the region by aligning with local militant actors and building durable insurgencies. Their growth has disrupted longstanding security relationships between Sahelian governments and France, the United States, and the United Kingdom, with many of these new states reorienting and seeking security support from Russia. This study develops a game-theoretic model to explain why jihadist expansion has strained traditional Western partnerships and encouraged governments to seek Russian assistance. We also present an alternative model demonstrating how negotiated settlements can reduce jihadist appeal and limit external rival influence. We show that jihadist groups enhance local militants’ capabilities, reducing prospects for negotiated settlements with host states. At the same time, jihadist intervention increases the political and military costs borne by Western partners, weakening their capacity to sustain long-term security commitments. These dynamics create opportunities for Russia to expand its influence by offering security services through mercenary forces that profit from ongoing conflict. We conclude that arming host states is likely to prolong conflict, whereas negotiation and peace aid can isolate jihadist groups and promote a more stable peace.Footnote1
Bapat et al. (2026) studied this question.