State responsibility 77 default of the State concerned,346 even if the resulting injury itself was accidental and unintended.347 the principle that wrongfulness is precluded has been accepted.351 (4) In drafting what became article 61 of the 1969 Vienna Convention, ILC took the view that force majeure was a circumstance precluding wrongfulness in relation to treaty performance, just as supervening impossibility of performance was a ground for termination of a treaty.348 The same view was taken at the United Nations Conference on the Law of Treaties.349 But in the interests of the stability of treaties, the Conference insisted on a narrow formulation of article 61 so far as treaty termination is concerned. The degree of difficulty associated with force majeure as a circumstance precluding wrongfulness, though considerable, is less than is required by article 61 for termination of a treaty on grounds of supervening impossibility, as ICJ pointed out in the GabčíkovoNagymaros Project case: (6) Apart from aerial incidents, the principle in article 23 is also recognized in relation to ships in innocent passage by article 14, paragraph 3, of the Convention on the Territorial Sea and the Contiguous Zone (the United Nations Convention on the Law of the Sea, art. 18, para. 2), as well as in article 7, paragraph 1, of the Convention on Transit Trade of Land-locked States. In these provisions, force majeure is incorporated as a constituent element of the relevant primary rule; nonetheless, its acceptance in these cases helps to confirm the existence of a general principle of international law to similar effect. Article 61, paragraph 1, requires the “permanent disappearance or destruction of an object indispensable for the execution” of the treaty to justify the termination of a treaty on grounds of impossibility of performance. During the conference, a proposal was made to extend the scope of the article by including in it cases such as the impossibility to make certain payments because of serious financial difficulties ... Although it was recognized that such situations could lead to a preclusion of the wrongfulness of non-performance by a party of its treaty obligations, the participating States were not prepared to consider such situations to be a ground for terminating or suspending a treaty, and preferred to limit themselves to a narrower concept.350 (5) In practice, many of the cases where “impossibility” has been relied upon have not involved actual impossibility as distinct from increased difficulty of performance and the plea of force majeure has accordingly failed. But cases of material impossibility have occurred, e.g. where a State aircraft is forced, due to damage or loss of control of the aircraft owing to weather, into the airspace of another State without the latter’s authorization. In such cases 346 For example, in relation to occurrences such as the bombing of La Chaux-de-Fonds by German airmen on 17 October 1915, and of Porrentruy by a French airman on 26 April 1917, ascribed to negligence on the part of the airmen, the belligerent undertook to punish the offenders and make reparation for the damage suffered (study prepared by the Secretariat, ibid., paras. 255–256). 347 For example, in 1906 an American officer on the USS Chattanooga was mortally wounded by a bullet from a French warship as his ship entered the Chinese harbour of Chefoo. The United States Government obtained reparation, having maintained that: “While the killing of Lieutenant England can only be viewed as an accident, it cannot be regarded as belonging to the unavoidable class whereby no responsibility is entailed. Indeed, it is not conceivable how it could have occurred without the contributory element of lack of proper precaution on the part of those officers of the Dupetit Thouars who were in responsible charge of the rifle firing practice and who failed to stop firing when the Chattanooga, in the course of her regular passage through the public channel, came into the line of fire.” M. M. Whiteman, Damages in International Law (Washington, D.C., United States Government Printing Office, 1937), vol. I, p. 221. See also the study prepared by the Secretariat (footnote 345 above), para. 130. 348 Yearbook … 1966, vol. II, p. 255. 349 See, e.g., the proposal of the representative of Mexico, United Nations Conference on the Law of Treaties, First and second sessions, Vienna, 26 March–24 May 1968 and 9 April–22 May 1969, Documents of the Conference (United Nations publication, Sales No. E.70.V.5), Report of the Committee of the Whole on its work at the first session of the Conference, document A/CONF.39/14, p. 182, para. 531 (a). 350 Gabčíkovo-Nagymaros Project (see footnote 27 above), p. 63, para. 102. (7) The principle has also been accepted by international tribunals. Mixed claims commissions have frequently cited the unforeseeability of attacks by rebels in denying the responsibility of the territorial State for resulting damage suffered by foreigners.352 In the Lighthouses arbitration, a lighthouse owned by a French company had been requisitioned by the Government of Greece in 1915 and was subsequently destroyed by enemy action. The arbitral tribunal denied the French claim for restoration of the lighthouse on grounds of force majeure.353 In the Russian Indemnity case, the principle was accepted but the plea of force majeure failed because the payment of the debt was not materially impossible.354 Force majeure was acknowledged as a general principle of law (though again the plea was rejected on the facts of the case) by PCIJ in the Serbian Loans and Brazilian Loans cases.355 More recently, in the “Rainbow Warrior” arbitration, France relied on force majeure as a circumstance precluding the wrongfulness of its conduct in removing the officers from Hao and not returning them following medical treatment. The tribunal dealt with the point briefly: New Zealand is right in asserting that the excuse of force majeure is not of relevance in this case because the test of its applicability is of 351 See, e.g., the cases of accidental intrusion into airspace attributable to weather, and the cases of accidental bombing of neutral territory attributable to navigational errors during the First World War discussed in the study prepared by the Secretariat (footnote 345 above), paras. 250–256. See also the exchanges of correspondence between the States concerned in the incidents involving United States military aircraft entering the airspace of Yugoslavia in 1946, United States of America, Department of State Bulletin (Washington, D.C.), vol. XV, No. 376 (15 September 1946), p. 502, reproduced in the study prepared by the Secretariat, para. 144, and the incident provoking the application to ICJ in 1954, I.C.J. Pleadings, Treatment in Hungary of Aircraft and Crew of the United States of America, p. 14 (note to the Hungarian Government of 17 March 1953). It is not always clear whether these cases are based on distress or force majeure. 352 See, e.g., the decision of the American-British Claims Commission in the Saint Albans Raid case, Moore, History and Digest, vol. IV, p. 4042 (1873), and the study prepared by the Secretariat (footnote 345 above), para. 339; the decisions of the United States-Venezuela Claims Commission in the Wipperman case, Moore, History and Digest, vol. III, p. 3039, and the study prepared by the Secretariat, paras. 349–350; De Brissot and others case (footnote 117 above), and the study prepared by the Secretariat, para. 352; and the decision of the BritishMexican Claims Commission in the Gill case, UNRIAA, vol. V (Sales No. 1952.V.3), p. 157 (1931), and the study prepared by the Secretariat, para. 463. 353 Lighthouses arbitration (see footnote 182 above), pp. 219–220. 354 UNRIAA, vol. XI (Sales No. 61.V.4), p. 421, at p. 443 (1912). 355 Serbian Loans, Judgment No. 14, 1929, P.C.I.J., Series A, No. 20, pp. 39–40; Brazilian Loans, Judgment No. 15, ibid., No. 21, p. 120.