Earlier this month, Peru's Supreme Court rejected the appeal of former President Alberto Fujimori of his 25-year sentence for murder and abduction, reaffirming the principle that no one is above the law. This is but the latest of several triumphs for human rights and accountability in the Andean nation. The United States would do well to study the Peruvian example. In 1992, the most brutal communist guerrilla group in Latin American history brought dozens of car bombs and political assassinations to Lima. A nation of more than 22 million, with a sophisticated, cosmopolitan capital, seemed unable to counter the threat...