On March 12, 2004, acting attorney general James B. Comey and the Justice Department’s top leadership reached the brink of resignation over electronic surveillance orders that they believed to be illegal. President George W. Bush backed down, halting secret foreign-intelligence-gathering operations that had crossed into domestic terrain. That morning marked the beginning of the end of STELLARWIND, the cover name for a set of four surveillance programs that brought Americans and American territory within the domain of the National Security Agency for the first time in decades. It was also a prelude to new legal structures that allowed Bush and...