JOSEF MRÁZEK CYIL 7 ȍ2016Ȏ e.g. under an “expanded doctrine of self-defence”, has no recourse in the UNCharter and is controversial. Various criteria for “legitimacy” were proposed to convey a principle for evaluating uses of force that differs from “strict legality”. This article does not aim to contribute crucially to the theoretical discourse on “legitimacy” in law. But the author refuses categorically any idea as to the priority to be given to “legitimacy” over international law norms. Feasibility of the state’s unilateral use of military force cannot from the legal point be assessed by reference to the concept of legitimacy. But it is true that “legitimacy” is often called in an effort to “justify” unilateral use of force, disregarding legal restrains in both the UN Charter and international customary law. The term “legitimacy” is explained e.g. as an alternative not only to morality but also to law. Martti Koskenniemi wrote that legitimacy is a “mediate concept that seems be rhetorically successful only so long as it cannot be pinned down to being either a formal rule or an incident of some controversial theory of justice.” 87 There is widespread scepticism as to the effectiveness of international law on the use of force with regard to the gap between the prohibition of the use of military force and real practice. The principle of the prohibition of force may contradict “legitimity” and existing moral values. The crucial question for international lawyers to solve is how far “divergences” from the prohibition of the use of force in the UN Charter should not be seen as breaches of international law but as a customary modification of this prohibition. There are a large number of legal problems and controversies about the prohibition of the use of armed force and its developments in customary international law. The principle of prohibition on the use of force has been considered to be a peremptory norm of general international law ( ius cogens ), as a cornerstone of the UN collective security system and as a basic rule of contemporary international public order.
87 KOSKENNIEMI, MARTTI. Legitimacy, Rights and Ideology: Notes Towards a Critique of the New Moral Internationalism. Associations: Journal for Legal & Social Theory. 2003, p. 349; AJIL. 2011, Vol. 105, p. 394.