The image of young men standing in formation being yelled at by a drill instructor, dropping to perform pushups on command, and responding to questions with a polite “yes, sir” or “no, ma’am” has struck a chord with Americans who want their criminal justice system to “get tough” on juvenile offenders. By the mid-1990s, thirty states had established military-style “boot camps” as an alternative to prison or probation for juveniles convicted of nonviolent crimes. The boot camps try to instill in the teens self-respect, discipline, a sense of responsibility, and a work ethic, and to motivate them to find jobs and become productive members of society. Most of the boot camps follow similar regimens: reveille seven days a week at 5 A.M.; followed by grueling marches and drills; physical training...