This contribution to the MLG-debate wants to focus on the question of legitimate authority for the use of military force in the framework of international interventions. More in particular, it is the main objective of this article to verify whether the international intervention in Former Yugoslavia (1991-1995) was characterised by a sufficient legitimate authority quality. The analysis itself will be developed in two steps. In a first step, we will describe the three main approaches to the concept of the legitimate authority in the post Cold War literature. Secondly, it is our intention to apply these three legitimate authority approaches in the context of the international intervention in Former Yugoslavia. The final results of this study allow us to formulate a rather remarkable conclusion from an ethical point ofview. Due to the reluctance of the international community to use military force, the central issue concerning the legitimate authority debate no longer seems to be "who among the many candidates has the right to intervene?", but rather 'who has the duty to do so?".