The Iran nuclear deal was officially implemented on Saturday, as Iran successfully fulfilled its initial key nuclear commitments and the international community relieved major sanctions, including unfreezing about $100 billion of Iranian money. Implementation Day was met with applause from deal supporters in the U.S. and Iran, while critics have raised questions about whether Iran will adhere to its requirements and how it will flex its newfound economic power. Also in recent days, the U.S. and Iran agreed to a prisoner swap that led to the freedom of Washington Post reporter Jason Rezaian and others, and negotiated the release of American sailors detained in Iran. What does the arrival of Implementation Day mean for Iran’s nuclear program and nuclear nonproliferation, and how does it bode for the future of U.S.-Iran relations? We asked Belfer Center experts to weigh in on these and related questions.