Had Iranians set out to find the absolute antithesis of Khatami to succeed him as president, they could not have achieved a more perfect paradox than Mahmoud Ahmadinejad. The 2005 presidential election instigated a dramatic transformation in the character of the presidency. Khatami, a genteel and literary cleric who valued dignity, respect, and rule of law, found himself replaced by a provocateur from the security forces who reveled in political strife. On domestic policy, where Khatami favored incrementalism, Ahmadinejad opted for shock therapy. Across the world, the reformist mantras of détente and dialogue among civilizations were jettisoned in favor of confrontation and creeping isolation.

Nowhere were the distinctions between the Khatami presidency and the Ahmadinejad era more evident than in the economy, where government policy, political debates, and actual conditions experienced striking shifts, mainly negative ones. Each of the perennial problems afflicting the economy – inflation, unemployment, corruption, and mismanagement – worsened during Ahmadinejad's eight years in office, despite a period of record oil revenues. These outcomes, and Ahmadinejad's legacy, are inextricably tied to the nuclear standoff and the 2009 elections upheaval, which together facilitated an unprecedented sanctions regime and severe disruptions to Iran's place in the global economy.

The Ahmadinejad era is best understood as the product of Iran's unique metamorphosis over the past three decades and is particularly rooted in the basic forces of Iran's postrevolutionary political economy. His populist rhetoric and program – particularly the ostentatious efforts to dispense the state's largesse after taking office – revived themes that were central to the early postrevolutionary period. The roller-coaster ride that was the eight-year presidency of Mahmoud Ahmadinejad may have been the most unexpected dimension of a political narrative that has been persistently unpredictable since its inception in 1979. As the scholar Ali Ansari commented, “(E)ven for those Iranians who were bored of politics, Ahmadinejad was making life dangerously interesting.”