Calling it a “great embarrassment” that fails to “halt Iran’s nuclear ambitions,” President Trump today announced his intention to pull out of the Joint Comprehensive Plan of Action and re-impose sanctions on Iran. The independent nuclear, national security, and regional experts of Harvard Kennedy School’s Belfer Center for Science and International Affairs have been assessing the terms of the JCPOA for years. In the wake of Trump’s decision, many of them weighed in with thoughts on the significance of Washington’s policy change – and what comes next.