The Dark Side of Extended Deterrence: Thinking through the State Sponsorship of Terrorism

States employ extended deterrence to shield third parties from aggression. The concept is traditionally applied to interstate relations, collective security arrangements, and strategic considerations. The protective relationship that exists between a state sponsor of terrorism and its non-state militant proxy is rarely considered. This article will introduce and explore the sponsor–proxy relationship in the context of extended deterrence, and relate it to Iran’s support and sponsorship of political violence, militancy, and terrorism in Europe. The article reviews the rationale states have for sponsoring terrorism, and illustrates the promises and pitfalls associated with extending deterrence to non-state militants.