Abstract For more than two decades, Iran’s nuclear programme has concerned policymakers and scholars alike. Whether speeding up uranium enrichment, slowing down international negotiations, or disrupting the timing of key initiatives, actions around Iran’s nuclear programme bear a clear time signature. Yet systematic accounts of the importance of time in shaping foreign and security policymaking have been largely neglected. Through foreign policy timing theory’s (FP4D) reconceptualisation of time we show how actors both constructed and then used time to pursue their strategic interests, creating, altering, and sabotaging the timing mechanism linking Iranian nuclear technology and international sanctions. These manipulations of time by both domestic and international actors resulted in prolonged international negotiations and fluctuating periods of crisis and produced a temporally flawed agreement frozen in time. We consider time’s impact on the current challenges and future direction of nuclear diplomacy with Iran as well as its importance for broader nuclear security issues.