A thousand Calleys -- pt. one. CONUS. The selection process -- The training process -- The evaluation process -- pt. two. Vietnam. Training in Vietnam -- Rules of engagement -- Atrocious behavior -- Discipline -- Conclusion: One Calley -- Appendix 1: Glossary -- Appendix 2: Historiographical essay -- Appendix 3: OCS leadership qualities and traits -- Appendix 4: Questionnaires and interviews.