This work examines topics that are considered to be especially relevant for making a strategic leader development investment. The areas covered have theoretical and empirical connections to important aspects of growth, change, adult development, and underlying abilities, skills and competencies needed to lead effectively in times of great complexity. In addition, these are investment areas identified by the US Army - a world-class organization faced with the need for radical transformation - as particularly relevant for success and survival. It identifies key concerns in developing leaders and leadership, and in transforming organizations to better meet the challenges of a complex world. The chapters that are collected in this volume were originally commissioned by the US Army Research Institute as "white papers" to better help Army officers and researchers understand important issues in leader development.