A relationship beset with extraordinary acrimony, the U.S. and Iran rarely see eye-to-eye, if only to avoid war or nuclear catastrophe. What is at the core of this troubled rivalry that has stymied policymakers and scholars alike? Using a carefully selected collection of White House, CIA, State Department, and other records, Worlds Apart provides a comprehensive answer to this question: starting from the 1979 revolution and hostage crisis, through the Iran-Iraq War and the spread of radical Islam, to 9/11 and the nuclear impasse, to the 2009 Green Movement and the Obama and Trump presidencies. The records, which form the heart of the book, offer a rare, unfiltered view into the perspectives and experiences of the American and Iranian governments over 40 years. Providing timelines, glossaries, discussion questions, and a guide on reading declassified documents, Byrne and Byrne explore this complicated relationship accessibly and innovatively in this unique documentary history.