157 inapplicable by reason of a United States exclusion of multilateral conventions as set out in its acceptance of the compulsory jurisdiction clause of the Statute of the Court. (I.C.J. Reports 1986, paras. 217-220 and 255; and see I.C.J. Reports 1984, p. 421, para. 67). 24. But this does not mean that the Court did not have to consider whether there was a use of force, for, altogether apart from the question whether there was a breach of the Geneva Conventions, Nicaragua, as has been seen, had claimed that "the United States, in breach of its obligation under general and customary international law, has used and is using force and the threat of force against Nicaragua..." ( I.C.J. Reports 1986, p. 19, para. 15(c)). That is the point involved here. In Nicaragua, the Court did not have to determine whether the conflict was internal or international; but it did have to determine whether the United States was using force against Nicaragua through the contras, and, on my interpretation, it did decide that there was such a use of force. If there was such a use of force by one state against another, ex definitione the conflict was international, whether or not it was necessary for the Court to decide that it was. 6. The Demonstrable Link Test Proposed by the Prosecution 25. As mentioned in paragraph 69 of the judgement of the Appeals Chamber, the prosecution submitted that the answer to the question whether the FRY was in armed conflict with BH through the VRS hinged on whether the conflict involved a "demonstrable link" between the VRS and the FRY or VJ, meaning, I believe, something less stringent than either of two tests which were discussed, namely, the agency test and the effective control test. The prosecution accepted that there was no authority to support the idea but thought that general jurisprudence would. In aid of the submission, recourse could be had to the character of the reference in Article 2, first paragraph, of the Fourth Geneva Convention to "all cases of declared war or of any other armed conflict which may arise between two or more of the High Contracting Parties... ". As it has been often observed, the expression "armed conflict" is a factual one, not intended to become burdened with legal technicalities: one respected commentator refers to it as "a de facto concept".3 26. That is true. However, there is a difference between saying that the question whether there is an armed conflict between states is a factual one and saying that, for that reason, it is not necessary to determine whether there is an armed conflict between