Lhasa, a sleepy, rather grubby backwater only 30 years ago, is now a city of huge public squares, shopping centers, and high-rise buildings, connected to the rest of China with a high-speed railway line. It is true that Tibetans, sparsely represented in local government, may not have benefited as much as the Han Chinese, whose presence in cities, such as Lhasa, as soldiers, traders, and prostitutes is so overwhelming that people worry about the extinction of Tibetan culture, except as an official tourist attraction.