•Stillman reported suspicions that a Soviet-era spy, code-named "Perseus," was still working at Los Alamos in the mid-'90s. Investigation into Perseus was botched, according to the book, amid the Wen Ho Lee case, in which investigators filed 59 espionage-related charges against the scientist. (The charges were later dropped to one, to which Lee pleaded guilty as part of a settlement.)
•Repeated visits by U.S. scientists to China suggest China designed and tested a bomb for Pakistan, which the authors view as the nation with the most dangerous weapons enterprise.
"Pakistan is different," Reed says, citing, among other issues, unstable politics and al-Qaeda sympathies among parts of the population.
In The Bomb, Younger, a senior scholar at the Woodrow Wilson International Center for Scholars and a former weapons designer, focuses on U.S. nuclear weapons. Congress has required a reassessment of the nuclear stockpile, part of a long-running political tussle over proposals to build new nuclear warheads.
"Our weapons are still locked in a Cold War, and it is time for us to examine again the question of what we intend with our weapons," says Younger, who intends his book as a corrective history that cuts through the fog of public misperceptions about nuclear weapons.
Browne says the questions about how nuclear weapons relate to international stability have become increasingly difficult in the modern world.
"Things were a lot easier, in many ways, when it was just us and the Russians," he says.