Rogoff traces the dollar's ascent over seven decades, from outcompeting the Soviet ruble, Japanese yen, and euro to its current role as the world's reserve currency, enabling the US to borrow cheaply and wield economic influence. He argues that luck, strategic policies, and global events propelled this dominance, but arrogance and fiscal irresponsibility now pose existential threats, potentially leading to inflation, loss of central bank independence, or a shift to alternatives like digital currencies. The book combines historical analysis with forward-looking warnings, emphasizing that the dollar's problems could become everyone's if unchecked, amid rising multipolarity and de-globalization.