International Peace Institute · CC BY 2.0

A conflict-resolution specialist who served on the U.S. peace team at the 2000 Camp David summit and later led the Obama administration's Middle East and anti-ISIS portfolios on the National Security Council. Biden named him special envoy for Iran in 2021 to negotiate a return to the 2015 nuclear deal; in 2023 his security clearance was revoked and he was placed on leave pending an investigation into his handling of classified information, later referred to the FBI.