Most accounts of the collapse of Richard Nixon’s presidency begin with Watergate — the now iconic tale of a bungled break-in and the misbegotten cover-up that followed. But what led to Watergate? How — and more puzzlingly, why — did one of the shrewdest, most gifted political figures of his time become embroiled in so manifestly lunatic an enterprise in the first place? Intrigued by that question, writer/journalist Kurt Andersen takes a deep dive into the vast archives at the Nixon Library and emerges with an answer he wasn’t expecting: While Watergate doubtless accelerated Nixon’s spectacular fall, it was the Vietnam War...