CYIL Vol. 7, 2016

JOSEF MRÁZEK CYIL 7 ȍ2016Ȏ use of force against their territory, against their ships, planes, military forces etc. as a “crime of aggression”. It might also be complicated to credibly recognize which acts of aggression have a “serious” or ”substantial” impact on violation of Art. 2 (4). The problem of the definition was and still is a matter of great controversy, even after Kampala. The term “aggression” itself has a long history (even behind the LN) and appeared as the casus foederic in many treaties of defensive alliances in the nineteenth century. In San Francisco some delegates equated the term “aggression” with “armed attack”. Other questions might also be discussed: What does the notion of “self-help” or “offensive self-help” in present international law mean? The Carolina case of 1837 is often used as a “mantra” just for “self-help” and “self-defence” reasoning in international customary law. Is a “threat to peace” a sufficient legal or “legitime” ground for unilateral use of armed force (armed intervention) without authorization of the UNSC? How should one assess “doctrines” on “implicit” or “ex-post facto” UNSC authorization of the use of armed force? Is it in this respect legally admissible to invoke even “tacit” authorization? Under which conditions may resort to armed force without authorization by the UNSC become “legitime” and be later “legally” justified? Can some NATO armed actions be legally realized without UNSC authorization? Is this Alliance organization already an organization of “collective security” or does it remain still only an organization of “self-defence” according to Art. 51? What is the legal reasoning of military actions against terrorist groups and other non-state actors against the state who shelter them? There is a likewise revival of the “just war” theories (see Obama’s declarations). 4 Who will now decide ultimately that a war is “just” or “unjust” ( bellum iniustum )? The medieval idea of bellum justum was actually not a rule either of positive international law nor of natural law. The theory of “just war” was developed by the theologian school of international law. Until the beginning of the 20 th century, the States were free to resort to war for any reason. As a rule a war was considered to be “just” by brother parties to the war. Is it legal to use armed force to protect one’s own nationals abroad without UNSC approval? Recently a so-called “accumulated armed attack” theory has appeared. Does this theory really find support in international law? There are surely many questions which are to be solved to clarify the content of the use of the armed force principle in international law, which seems to be losing significance due to many violations of it, despite being “justified” by various legal theories and doctrines. This article concentrates on some of those items which have been summarized in the following five chapters:

4 President Obama’s Peace Prize Lecture. AJIL. 2010, No. 1, pp. 127-129.


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