Twenty-five years ago this summer, the guns finally fell silent in Korea, ending a bitter 37-month "limited war" that cost 34,000 American lives and engendered fierce political controversy at home. America's Korea veterans are now well into middle age, their efforts against the Chinese and North Korean invaders sel- dom remembered. But they succeeded in repelling Communist aggression, and the shock of that aggression changed modern American attitudes toward national security. The war's...