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Updated on 1 March 2021


Section 12:   Communications


A historical overview of reporting under Article 51 on actions taken in self-defence (with Table)


In communications to the Security Council, the inherent right to act in self-defence, as preserved by Article 51 of the UN Charter, has been cited by a number of Member States which have referenced it sometimes as a general principle of international law and sometimes with regard to a specific situation.  However, a reporting requirement exists under Article 51 whenever action is actually taken in self-defence:


“Measures taken by Members in the exercise of this right of self-defence shall be immediately reported to the Security Council”. 


In the Council’s early years, some Member States requested the convening of a Council meeting expressly to report pursuant to Article 51.  Soon, however, it became the common practice for States to report pursuant to Article 51 by sending letters to the Council President or, less frequently, to the Secretary-General. 


It is sometimes difficult to distinguish letters which merely invoke Article 51 as a right which might be exercised in future –  in effect, as a warning  – from letters which have been sent with the intention of fulfilling the reporting requirement of Article 51.  The Table below sets out 100 cases of statements during Council meetings or letters which cite Article 51 in such a way that they might be considered “reporting” pursuant to that article.  The table also includes, however, letters which are somewhat ambiguous.


Keeping this ambiguity in mind, Argentina and the United Kingdom have reported the most frequently pursuant to Article 51, owing to the series of such communications which they sent at the time of the 1982 Falkland Islands/Las Malvinas conflict.  In that connection, 28 letters citing Article 51 were sent by Argentina, and 20 by the United Kingdom.


Otherwise, the United States has reported the most often pursuant to Article 51 – on seventeen occasions.  Iran has reported on twelve occasions; Israel, seven or possibly eight (see related article on this site); the Democratic Republic of the Congo, four; and Egypt, three. 


Turkey has reported between six and eight times.  It is not possible to give an exact number because the information contained in letters invoking Article 51 sent by the Turkish representative cannot be correlated definitively with the several parallel, ongoing operations launched by Turkey in Syria and Iraq from 2015 to the present. 


The United Kingdom has reported four times on matters other than the Falkland Islands/Islas Malvinas.  Reporting twice have been Australia, Canada, Chad, France, Germany, Liberia, Libya, the Netherlands and the Sudan.  Reporting one time each have been Azerbaijan, Bahrain, Belgium, Cambodia, Côte d’Ivoire, Croatia, Denmark, Ecuador, Ethiopia, Georgia, Iraq, Kuwait, Lebanon, New Zealand, Norway, Poland, Qatar, Rwanda, the Russian Federation, Saudi Arabia, Syria, Tajikistan, Tanzania, Thailand, Tunisia, the United Arab Emirates, Yugoslavia and Zimbabwe. 


In its judgement of 27 June 1986, in the case brought by Nicaragua against the United States for arming the Contras and mining Nicaragua’s harbors, the International Court of Justice stated that “the absence of a report” to the Security Council pursuant to Article 51 “may be one of the factors indicating whether the State in question was itself convinced that it was acting in self-defence”.  It is not possible to know the extent to which this judgement has influenced the decisions of UN Member States to report instances of purported self-defence to the Security Council.  However, it may be one factor contributing to the fact that during the 40 years prior to the ICJ judgement, 16 cases of reporting to the Council pursuant to Article 51 occurred.  In the 33 years following the ICJ judgement, there have been 79 cases.* 


Some specific reporting patterns pursuant to Article 51 have emerged since 2014, especially in the context of ISIL/Da’esh and the situations in Syria and Iraq.  For details of these various trends, see related articles on this website for reporting during the periods 2014-15, 2016-17 and 2018-19.


(This update supplements page 438 of the book.)


* The series of letters relating to the Falkland Islands/Islas Malvinas conflict have been counted as one case for Argentina and one case for the United Kingdom.

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