El Salvador's civil war, which left at least 75,000 people dead and displaced more than a million, ended in 1992. The accord between the government and the Farabundo Marti National Liberation Front (FMLN) has been lauded as a model post-Cold War peace agreement. But after the conflict stopped, crime rates shot up. The number of murder victims surpassed wartime death tolls. Those who once feared the police and the state became frustrated by their lack of action. Peace was not what Salvadorans had hoped it would be. Citizens began saying to each other, "It's worse than the war."

"El...