Use of force by states

The use of force by states is controlled by both customary international law and by treaty law. The UN Charter reads in article 2(4):

All members shall refrain in their international relations from the threat or use of force against the territorial integrity or political independence of any state, or in any other manner inconsistent with the purposes of the United Nations.

This rule was "enshrined in the United Nations Charter in 1945 for a good reason: to prevent states from using force as they felt so inclined", said Louise Doswald-Beck, Secretary-General International Commission of Jurists.

Although some commentators interpret Article 2(4) as banning only the use of force directed at the territorial integrity or political independence of a state, the more widely held opinion is that these are merely intensifiers, and that the article constitutes a general prohibition, subject only to the exceptions stated in the Charter (self-defence and Chapter VII action by the Security Council). The latter interpretation is also supported by the historic context in which the Charter was drafted, the preamble specifically states that "to save succeeding generations from the scourge of war, which twice in our lifetime has brought untold sorrow to mankind" is a principal aim of the UN as such. This principle is now considered to be a part of customary international law, and has the effect of banning the use of armed force except for two situations authorized by the UN Charter. Firstly, the Security Council, under powers granted in articles 24 and 25, and Chapter VII of the Charter, may authorize collective action to maintain or enforce international peace and security. Secondly, Article 51 also states that: "Nothing in the present Charter shall impair the inherent right to individual or collective self-defence if an armed attack occurs against a state." There are also more controversial claims by some states of a right of humanitarian intervention, reprisals and the protection of nationals abroad.

Article 2(4) does not use the term "war" but rather refers to "the threat or use of force." Although clearly encompassed by the article, it is ambiguous whether the article only refers to military force or economic, political, ideological or psychological force. The Preamble to the Charter declares that the "armed force shall not be used, save in the common interest..." Article 51 preserves the "right of individual or collective self defence if an armed attack occurs...". In 1970 the General Assembly adopted the Declaration on Principles of International Law Concerning Friendly Relations and Co-operation Among States in Accordance with the Charter of the United Nations. This resolution was adopted without vote by consensus but is considered an authoritative statement on the interpretation of certain provisions of the Charter. The Declaration reiterates article 2(4) and elaborates upon the occasions when the threat or use of force is prohibited but it does not address the question of whether force includes non-military force within the scope of the Charter. The Declaration also states that: "Nothing in the foregoing paragraphs shall be the construed as enlarging or diminishing in any way the scope of the provisions of the Charter concerning cases in which the use of force is lawful." Certain types of armed and non-armed intervention are prohibited by the Declaration: "No State or group of States has the right to intervene, directly or indirectly, for any reason whatever, in the internal or external affairs of any other State. Consequently, armed intervention and all against its political, economic and cultural elements, are in violation of international law." The Declaration addresses the use of non-military force in the context of other international obligations such as the obligation not to intervene in the affairs of another state.

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Wikipedia