It is widely held that long‐term relationships between buyers and suppliers are beneficial for both parties. This view has become axiomatic in contemporary management. However, little empirical evidence exists to support the benefits of long‐ versus short‐term relationships. This study examines the degree to which export relationships can be sustained over time, thus producing mutual benefits for the parties involved. The perceptions of 212 UK export managers from a broad range of industrial sectors were obtained. Using relationship duration as a categorising variable four groups of international relationships were examined based on relationship elements (e.g. trust, commitment) and performance components (e.g. relationship costs, value). The findings reveal that there is some weakening of the relationships over time as is illustrated in terms of the reduced level of affective commitment; however, perceptions of competence and performance show signs of significant increase. Further, the findings indicate that exporters in relationships with a high relational content (e.g. trust, commitment) generally achieve higher than average performance outcomes. Long‐term relationships do indeed suffer from a “dark side”; however, this is lightened by a mutual appreciation of competencies that enable sustained performance.