The ICJ in its order dated 16 March 2022, decided that the legality of the unilateral use of force to prevent acts of genocide is ‘doubtful’. Based on this order, it is possible to say that the ICJ provides a yellow light to unilateral use of force for the prevention of acts of genocide. But the ICJ expressed its opinion in this respect in 2007, underlining that every state may only act within the limits permitted by international law. The doctrine underscored that the unilateral use of force for the prevention of genocide was forbidden. In this situation, the following question arises: is it really doubtful? To find the answer to this question, it is necessary to examine the legal basis and means for the prevention of genocide. In this article, the legality of the unilateral use of force for the obligation to prevent genocide has been comprehensively discussed.