The telecom sector has changed dramatically during the last decade. In order to meet new regulations, fierce competition and a growing demand for cheap and high quality telecom services by multinationals, European public telecom operators have created pan-European strategic alliances. This paper focuses on the question of how Unisource, an alliance of Swedish Telia, Dutch KPN Telecom, Swiss Telecom and Spanish Telefó nica has coped with the control vs commitment dilemma. The four telecom providers wanted to merge their activities with Unisource. To create commitment and trust the parents used a synergy strategy to deal with cultural diversity. Unisource was started in 1992, but finally collapsed in 1999 due to lack of commitment. The crisis in Unisource shows the dilemma of control vs commitment in a dynamic transition process of organisations. © Emerald Group Publishing Limited.