From Nuclear Deterrence to Regional War: Future Trajectories of the US-Israel-Iran Conflict and the Changing Global Order

On 28 February 2026, joint US-Israeli strikes on Iran turned a long-running nuclear confrontation into a regional war that remains unresolved more than seven months later. This article examines how the confrontation moved from nuclear deterrence to open conflict. What its geopolitical and geoeconomic consequences have been, and which trajectories are most plausible? Drawing on deterrence and preventive war theory, balance of threat realism, geoeconomics and power transition scholarship, it uses process tracing and scenario analysis based on open-source evidence available up to 7 October 2026. It finds that deterrence failed because of a preventive war logic established after the 2025 strikes and the decapitation of Iran’s leadership, and negotiation under military pressure. The war’s centre of gravity then shifted from the nuclear programme to control of maritime chokepoints, i.e. the Strait of Hormuz and the Bab el-Mandeb. The conflict has regionalised security, pushing Gulf states towards hedging. It hardened rather than collapsed the Iranian state, and imposed uneven economic costs on import dependent economies such as India. Three scenarios are developed i.e. conditional de-escalation, protracted stalemate and major re-escalation. Protracted stalemate punctuated by re-escalation is judged most likely. The article argues that the war accelerates, but does not complete, the erosion of US primacy, producing a fragmented, multi-aligned order in which middle powers and chokepoint leverage matter more than formal blocs.