A missing Iranian nuclear scientist has taken refuge in the Iranian interests section of the Pakistani Embassy in Washington. The scientist, Shahram Amiri, disappeared during a pilgrimage to Saudi Arabia a year ago. His whereabouts have been a mystery ever since. In March, ABC News said the scientist had defected to the United States and was helping the CIA, but Iran has claimed that he was kidnapped by the CIA and Saudi intelligence agents. The United States government has never acknowledged Amiri’s existence or admitted to a role in his disappearance.