The time has come for a new policy towards Iran. The US-led policy of deterrence has failed spectacularly. Its two goals were to prevent Iran from acquiring a nuclear bomb and to contain Iran’s aggression in the Middle East. Now, Iran is on the brink of acquiring a nuclear weapon, has extended its sphere of influence across the region and, on 13 April 2024, directly attacked Israel for the first time.

This paper analyses Iran’s grand strategy in the Middle East and explains how the US and Israel have contributed to the failure of deterrence. It argues that for too long, Iranian aggression has been unchallenged. Even when the US has been directly targeted by Iranian proxies, successive administrations have refused to respond directly to Iran and hold the regime accountable. The strategy was to localise conflict, avoid regional escalation and prevent broader war from breaking out in the Middle East. Ironically, it has led to the exact opposite. By attempting to prevent war, the US has encouraged conflict to erupt. The reason why: the calculus of the Iranian regime is primarily driven by regime survival and fosters disruption to insulate itself and extend its strategic depth. As such, Tehran responds to strength not diplomacy.