Taiwan has come close to developing nuclear weapons on two occasions, in 1977 and again in 1988, despite constant pledges to the United States that it was doing no such thing. Only the most persistent surveillance and intense pressure from Washington ended the program. The nonproliferation experts Albright and Stricker offer the most complete version yet told of this little-known story, based partly on the recollections of a high-ranking CIA informant inside the program. A key lesson is that nuclear enrichment programs are seldom for truly peaceful purposes, as their developers often claim. Even after pledges of nonproliferation and acceptance of inspection regimes, the temptation to cheat remains strong so long as enrichment and R & D facilities are still in place. The authors believe that Taiwan is more secure without nuclear weapons than it would have been with them. But the opposite argument will never lose its appeal—in Taiwan or, for that matter, in Japan, Saudi Arabia, or South Korea—so long as American allies have a shred of doubt about the reliability of the U.S. commitment to defend them against nuclear-armed rivals.