In today's times, more and more companies pursue global sourcing strategies in some form and to some extent. The most prominent reason for the increased interest in global sourcing is the idea to benefit from factor cost differences between sourcing regions. However, recent research indicates that cross-border sourcing is no panacea to generate cost savings. There are situations in which international sourcing does not lead to the intended price reductions or even causes expensive backsourcing activities. Accordingly, the ambiguous image of global sourcing is the point of departure for the dissertation at hand. Thus, the main purpose of this thesis is to explore how global sourcing can contribute to a firm's purchasing performance. The results indicate that the accumulation of social capital between the buying organisation and its international suppliers can increase the sourcing success. However, given the limited amount of resources for those intimate buyer-supplier relationships, close partnerships cannot be maintained with all suppliers. Consequently, the research at hand points in the direction that global sourcing can be a means to increase the intensity of competition in supply markets, facilitating the pursuit of more adversarial relationships.