At least 7 million young Americans--fully one-quarter of adolescents 10 to 17 years old--may be at risk of failing to achieve productive adult lives. They use drugs, engage in unprotected sex, drop out of school, and sometimes commit crimes, effectively closing the door to their own futures. And the costs to society are enormous: school and social services are overwhelmed, and our nation faces the future with a diminished citizenry. This...