Several protocols have been proposed to deal with the group key management problem in mobile ad hoc networks. Most of these protocols organize the network into clusters to reduce the cost of key refresh or rekeying. Rekeying constitues a challenging issue in group key management because it must be launched whenever the constitution of the group is altered following a leave or a join operation. However, cluster maintenance may also generate sinifficative communication overhead. So, the clustering algorithm is an important factor in the performance of any key management solution. A clustering algorithm that ensures stable clusters in spite of mobility is very appreciable in mobile ad hoc networks. In fact, all the overhead due to the traffic generated by cluster adjustments and the related rekeying procedures will be saved. As far as we know, no existing clustering algorithm takes into account self-stabilization while relying on the mobility resilience of graph alliances. In this paper, we propose a fully distributed and self-stabilizing clustering algorithm for key management in MANETs where each cluster is an alliance.