In one of the most comprehensive analyses of business relationships ever written, Greenhalgh shows how relationships -- not technology or "know-how" -- are the foundation of the new extended enterprise. In immensely readable prose, he describes how companies have moved beyond adversarial relationships of command-and-control hierarchies to a new communal world in which internal networks of autonomous professionals and external networks of collaborating organizations compete against rival networks. In order to manage, managers must acquire a whole new set of negotiating skills, he argues. Traditional negotiating techniques promoted winning and self-interest, leaving a wake of bitterness and acrimony. Here Greenhalgh introduces for the first time a brilliant concept he calls "Commonwealth," which promotes ongoing relationships and the common interest. Using scores of detailed case studies and examples, he offers a set of cutting-edge tools managers can apply immediately to repair and improve relationships between people at all levels of responsibility, between groups, between organizations themselves, and between personalities involving gender differences.