Contrary to what may seem at first glance, critical international law is not an international narrative of critical legal studies. However, critical legal studies (CLS), along with global critiques of liberalism, have made an effective contribution to the development of critical international legal theory. The present paper, with the purpose of explaining a broader concept of critical international law, seeks to show that any approach to international law, which by questioning and re-reading its belief system and procedures, seeks to policy window opening and show inconsistencies between the promises and the ends of international law and the existing reality of international relations, or in other words seeks to show the distance between the status quo and the desired state of the international legal order, and refers this inconsistency to the limitation of the structure or functioning of the international legal system, and provides agendas towards transformation or renewing the values, structure or function of this system, generally has a potential critical capacity. A review of the most prominent examples of critical approaches in the international law scholarship and the examination of their fundamental claims, along with expressing the most important criticisms, shows that the critical approach by emphasizing problem-raising rather than problem-solving and a redoubled attention to the role of international lawyers, offers a great potential for the gradual and progressive development of international law, and by confronting the depoliticization of international law, seeks to participate more actively in re-shaping the global legal order. From this perspective, the critical approach is an episteme towards hope, dynamism, and evolution.