Much has changed since the enactment of the Joint Comprehensive Plan of Action. Developments in recent years have reduced nuclear warheads to just one part of a larger, deadlier arsenal Iran is honing. (This is described in the 2019 Worldwide Threat Assessment.) Consequently, it will not be enough to resurrect the JCPOA. An enhanced deal must be negotiated. The incoming Biden administration should not rush this process, even though hardliners are poised to take control of Iran in a few months.
