Well, there’s the rub. If you crack open Trita Parsi’s new book, you will learn that on a fateful day in 2003, an “opportunity for a major breakthrough had been willfully wasted.” Parsi — the president of the National Iranian American Council, a self-described “nonpartisan, nonprofit organization dedicated to advancing the interests of the Iranian-American community” — begins “A Single Roll of the Dice,” his examination of President Obama’s diplomacy with Iran, with what has come to be known as the Guldimann memo. This was a putative Iranian offer in 2003 of comprehensive negotiations between the Islamic republic of Iran and the United States, delivered by the Swiss ambassador to Iran at the time, Tim Guldimann.

Parsi details the contents of the memo, which included an offer to end Iranian support for Hamas and Palestinian Islamic Jihad, pressure the terrorist groups to stop their attacks on Israel, support disarming Hezbollah in Lebanon, agree to intrusive international inspections for the Iranian nuclear program, and accept the Arab League’s Beirut Declaration, which offered peace with Israel in exchange for a complete Israeli withdrawal to pre-1967 lines.

The offer, which has swelled to biblical proportions in certain circles, was never pursued by the Bush administration, which doubted its authenticity. Whether or not it was as sincere as Parsi believes is almost beside the point. What matters is which side of the question you fall on: If you believe in Iran’s honest intentions, then Parsi’s book is for you; if you are a doubter, the author will seem a not-quite-disinterested observer.

The account of the Guldimann episode is rife with unnecessary and inaccurate biases: Bush Defense Secretary Donald Rumsfeld and Vice President Dick Cheney are described as neocons — an odd political handle for a defense secretary totally uninterested in regime change in Iraq and a vice president who continues to be a close ally of the Wahhabi monarchs in Saudi Arabia; Israel is portrayed as hostile to any deal with Iran that “would come at the expense of America’s special friendship with the Jewish state”; and Sunni Arabs are accused of colluding with Israel to take down Hamas, because to do so would hurt Iran.

After his election in 2008, Obama could not have been more explicit in his repudiation of Bush’s freedom agenda and his “Axis of Evil” foreign policy. Obama’s rivals (including his presidential opponent and now Secretary of State Hillary Rodham Clinton) vilified him for his willingness to sit down with the enemy, labeling him a naif and worse. But the American people were having none of it: Obama advertised an extended hand and received a mandate. Fans, particularly those who fretted about the lack of real dialogue with Iran, were elated. But disillusionment soon followed.