In an environment of rapid and discontinuous change, managers have turned to alliances to access the resources they need. But research on alliances shows that more than half fail, demonstrating the difficulty of managing these relationships. Based on their extensive research on alliances, the authors explore the relational capabilities needed for building and managing successful alliances. Using the case of Royal Philips, they explore the role of strategy, structure, systems, people, and culture in alliance success. They also discuss the need for ongoing adaptation and renewal of relational capabilities as the business and its environment change.