¹ Such an aircraft is referred to in this article as “intruding aircraft” or “intruder”; entry without permission is referred to as “intrusion.” These terras and the discussion that follows are not intended to apply to enemy aircraft in time of armed conflict or war.

² “Distress Condition” was defined in draft Technical Annex B to the Chicago Convention on International Civil Aviation (Treaties and Other International Acts Series, No. 1591) as “a condition in which an aircraft can no longer be operated safely, or is forced down.” Sec. I(z). In Annex 12 on Search and Rescue as adopted by the Council of the International Civil Aviation Organization (2nd ed., Sept., 1952, p. 7), “distress” is defined as “a state of being threatened by serious and imminent danger and of requiring immediate assistance.” In Annex 11 on Air Traffic Services, similarly adopted (2nd ed., May, 1952, p. 7), “Distress Phase” is defined as “a situation wherein there is reasonable certainty that an aircraft and its occupants are threatened by grave and imminent danger or require immediate assistance.” It is distinguished from “Alert Phase” in which “apprehension exists as to the safety of an aircraft and its occupants” and from “Uncertainty Phase” in which uncertainty exists as to such safety. These definitions, it must be noted, have been formulated for specific technical purposes and are, moreover, not legally binding on members of ICAO, since the Annexes are “international standards and recommended practices” rather than binding enactments or agreements. For earlier discussions and attempted definitions of distress and related concepts in air law, see Oëx, op, cit. (below, note 5), at pp. 1–5, 16–17. For distress and its legal consequences in international maritime law, see Jessup, The Law of Territorial Waters and Maritime Jurisdiction (1927), pp. 194–208, 220–221, 254–255, 258–263, 450, 466. See also note 105 below.

³ The term “state aircraft” is used in this article in the sense defined in Art. 3 of the Chicago Convention. It is to be noted that this definition appears to exclude aircraft owned by a state and employed by it in some strictly governmental functions such as civil aeronautics administration (e.g., aircraft operated by CAA in the United States) or diplomacy (e.g., aircraft attached to diplomatic missions abroad).

⁴ See, however, Kroell, , Traité de Droit International Public Aérien (1934), Vol. 1, p. 152 Google Scholar et seq.

⁵ Fauchille, , Traité de Droit International Public (1925), Vol. 1, 2nd Part, pp. 1159–1160 Google Scholar; Giuliano, La Navigazione Aerea nel Diritto Internazionale Generale (1941), p. 172; Podestá Costa, Manual de Derecho International Público (2nd ed., 1947), p. 160; Meyer, Compendio de Derecho Aeronáutico (1947), p. 282; Fenwick, International Law (3rd ed., 1948), p. 413; and a special study by Oëx, R., Das Internationale Notlanderecht der Luftfahrzeuge im Friedenszeiten (Dissertation, W.-Elberfeld, Leipzig, 1934)Google Scholar, cf. review in Archiv für Luftrecht, Vol. 4 (1934), p. 313. See also note 13 below.

⁶ See Roper, La Convention Internationale du 13 Octobre 1919 (1930), p. 160.

⁷ For practice in the early period see, e.g., Rolland in 20 Revue Générale de Droit International Public (1913) 395–408; 16 ibid. (1909), Documents 40; 18 ibid. (1911) 363; Spaight, Aircraft in Peace and the Law (1919), p. 47; Le Goff, Traité Théorique et Pratique de Droit Aérien (1934), pp. 40–42; Kroell, op. cit., at pp. 36, 138; Cooper in 19 Journal of Air Law and Commerce (1952) 128–129.

⁸ For the text and a discussion of this agreement, see Rolland in 20 Revue Générale de Droit International Public (1913) 697.

⁹ For World War I practice see, e.g., 7 Hackworth, Digest of International Law 549–553, and sources there cited; Harvard Research Draft Convention on Rights and Duties of Neutral States in Naval and Aerial War, with Comment, this Journal, Supp., Vol. 33 (1939), pp. 766–767; Spaight, Aircraft in Peace and the Law (1919), pp. 203–215; Hackwitz, Die Neutralität im Luftkriegsrecht (1927), pp. 52–59, 66–69; Zondag, Neutraliteit in de Lucht (1940), pp. 59–65; Spaight, Air Power and War Rights (3rd ed., 1947), pp. 420–423; François, Handboek van het Volkenrecht (1950), Vol. 2, pp. 678–682.

¹⁰ See, e.g., the Swiss ordinance of Aug. 4, 1914, and the Italian decree of Sept. 3, 1914, U. S. Naval War College, International Law Situations, 1926, pp. 101, 114.

¹¹ “In the interest of the defense of the state no less than in view of the maintenance of a strict neutrality a neutral Power has the right to oppose forcibly all passage of its frontiers by belligerent airships unless they should indicate by a signal—white flag or other distinctive sign—their intention to land. Considerations of humanity may lead the authorities to resort to force only after having tried to warn the aviator that he is above neutral territory, but in view of the foregoing such notice is not obligatory.” Note of March 18, 1916, as translated in 7 Hackworth, op. cit., at pp. 552–553. See also Spaight, Aircraft in Peace and the Law (1919), pp. 204–206. For official texts of correspondence see the Netherlands Orange Books (Overzicht, etc.), 1914–1915, pp. 26–28; 1915–1916, pp. 24–27; July–Dec, 1916, pp. 23–27.

¹² 7 Hackworth, op. cit. at p. 553; Netherlands Orange Book, 1915–1916, pp. 25–27; ibid., July–Dec, 1916, pp. 25–27. A similar arrangement was made with France and Belgium, ibid., 1916–1918, p. 51.

¹³ For various views see, e.g., Garner, , International Law and the World War (1920), Vol. 1, pp. 471–483 Google Scholar; Mérignhac, and Lémonon, , Droit des Gens et la Guerre de 1914–1918 (1921), Vol. 2, p. 410 Google Scholar; Fauchille, op. cit., at p. 765; Sandiford in 39 Revue Générale de Droit International Public (1932) 739; Balladore-Pallieri, La Guerra (1935), pp. 422–423; Kroell, op. cit., Vol. 2, at pp. 285–286; Le Goff, op. cit., Supplement (1939), p. 128; Spaight, Air Power and War Rights (3rd ed., 1947), pp. 421–422; Podestá Costa, op. cit., at p. 435; François, op. cit., Vol. 2, at pp. 683–684; Guggenheim, , Lehrbuch des Völkerrechts (1951), Vol. 2, pp. 992–994 Google Scholar; Akademiya Nauk SSSR, Institut Prava, Mezhdunarodnoe Pravo (1951), pp. 555–556; Oppenheim, International Law (7th ed. by Lauterpacht, 1952), Vol. 2, p. 725; Zondag, op. cit., at pp. 80–81.

¹⁴ This Journal, Supp., Vol. 32 (1938), pp. 12, 36. The same principle was embodied in Art. 95 of the Harvard Researeh Draft Convention, loc. cit., p. 764.

¹⁵ This Journal, Supp., Vol. 32 (1938), p. 35.

¹⁶ Meyer, Das Neutralitätsrecht in Luftkriege (1931), p. 71. Cf. Spaight, Air Power and War Rights (3rd ed., 1947), p. 436.

¹⁷ For text, see 11 League of Nations Treaty Series 173, or U. S. Treaties, etc. (Redmond), Vol. 3, p. 3768.

¹⁸ See Art. 38 of the convention, which reserves the freedom of action of the parties as belligerents or neutrals in case of war.

¹⁹ Art. 1.

²⁰ Art. 32 was worded as follows:

“No military aircraft of a contracting State shall fly over the territory of another contracting State nor land thereon without special authorization. In case of such authorization the military aircraft shall enjoy, in principle, in the absence of special stipulation the privileges which are customarily accorded to foreign ships of war.

“A military aircraft which is forced to land or which is requested or summoned to land shall by reason thereof acquire no right to the privileges referred to in the above paragraph.”

For clarification on the basis of preparatory work, see Roper, op. cit., at pp. 159–162; see also Kroell, op. cit., Vol. 1, at pp. 158–161.

²¹ Art. 33.

²² Arts. 2 and 15 (for clarifying amendment of Art. 15, see 138 League of Nations Treaty Series 418, 421).

²³ Art. 3 as amended in 1929, 138 League of Nations Treaty Series 418, 419.

²⁴ Art. 15.

²⁵ Art. 4.

²⁸ Art. 15.

²⁷ Very similar to the Paris Convention was the Ibero-American Convention on Aerial Navigation signed at Madrid in 1926, which, however, remained without practical effect. Hudson, International Legislation, Vol. 3, p. 2019. Generally similar was also the Pan American Convention on Commercial Aviation signed at Havana in 1928, 47 Stat. 1901, U. S. Treaties, etc. (Trenwith), Vol. 4, p. 4729, which, however, had no provisions on the privileges to be accorded to foreign military and other state aircraft.

²⁸ See, e.g., Klein, Staatsschiffe und Staatsluftfahrzeuge im Völkerrecht (1934), pp. 41–45; Antokoletz, Tratado de Derecho International Público (3rd ed., 1938), Part III, p. 45; Goedhuis, Handboek voor het Luchtrecht (1943), p. 54;. Tapia Salinas, Manual de Derecho Aeronáutico (1944), p. 104; Hyde, International Law Chiefly as Interpreted and Applied by the United States (2nd ed., 1945), Vol. 2, pp. 840–841; Meyer, Compendio de Derecho Aeronáutico (1947), pp. 284–285, note 162. But cf. Oäx, op. cit., at pp. 20–21; and Kroell, op. cit., Vol. 1, pp. 159–160, where it is suggested that the omission of comparable provisions from the Havana Convention indicates an intention to apply different rules. This suggestion is of doubtful merit, since the Havana Convention purported to deal only with civil aviation, as its Arts. 2 and 3 indicate. Cf. also note 49 below.

²⁹ Kroell, op. cit., Vol. 1, p. 138. Fauchille, writing before these incidents, maintained that the crews of intruding military aircraft could be punished, but that the aircraft should be repatriated subject to reimbursement of expenses. Op. cit. (supra, note 5), pp. 1159–1160.

³⁰ In January, 1931, two Polish military aircraft landed in Oppeln. The German court found that the leading pilot entered Germany by mistake, but that his mistake was due to negligence, and sentenced him to two weeks’ imprisonment on a charge of having crossed the German frontier without the requisite permit. A separate charge of violation of regulations governing the entry of foreign aircraft was dismissed on the ground that the penalties prescribed for such violation (a fine of not more than 150 marks or detention (Haft)) were of a subsidiary nature and to be applied only if no heavier penalties were applicable under other provisions of the law. The second pilot was acquitted on the ground that he was following the leader and was not himself guilty of negligence. 1 Archiv für Luftrecht (1931) 72. In May, 1931, a Polish military aircraft landed in East Prussia. The pilot, after getting directions from local inhabitants, took off in the hope of reaching Poland, but was forced by lack of oil to land again within German territory. The German court found that the pilot entered German territory by mistake, but that the mistake was due to negligence; it said that military flyers were under a duty to exercise special care not to violate the sovereignty of a foreign state. It also found that the pilot knew he was in German territory when he resumed his flight. He was convicted and sentenced to three days’ imprisonment on a charge of having crossed the German frontier without the requisite permit; and to seven days’ detention on a separate charge of having violated the regulations governing the navigation of foreign aircraft by resuming flight without the permission of German authorities. Ibid., p. 154. Also in May, 1931, three French military aircraft landed at Schweinfurt. The German court found that the aircraft entered Germany by mistake, but that the mistake was due to the pilots’ negligence. The leading pilot was sentenced to a fine of 250 marks and the other two pilots to fines of 100 marks each on charges of having crossed the German frontier without the requisite permits and of having violated the regulations governing the entry of foreign aircraft. Ibid., p. 267. These three cases occurred shortly after the termination in 1930 of the Allied occupation of the Rhineland, with which the right of transit and landing for Allied military aircraft in Germany under Art. 200 of the Treaty of Versailles lapsed. In none of the three reports is there any mention of confiscation of the aircraft. For a case involving a Soviet military aircraft in Estonia, see Oëx, op. cit., at pp. 9–10, footnote 39.

³¹ See, e.g., 2 Hackworth 305–306. Cf. Kroell, op. cit., Vol. 1, p. 156.

³² U. S. Department of State, The Treaty of Versailles and After (1947), p. 645; cf. Kroell, op. cit., Vol. 1, pp. 156, 207. A French airliner which made a forced landing while on an unauthorized flight over Germany was reported seized but its pilot released. Revue Juridique Internationale de la Locomotion Aérienne, 1923, pp. 291–292. A private French flyer who crash-landed in Germany was fined 5000 marks. Ibid., 1925, p. 425. For cases of foreign military intruders in Germany, see note 30 above. See, further, Oëx, op. cit., pp. 9–10, 24, footnotes.

³³ See provisions of the British Air Navigation Order, 1923, which, it may be noted, apparently applied to foreign military as well as civil aircraft, but exempted from punishment infractions “due to accident, stress of weather or other unavoidable cause.” Shawcross and Beaumont, Air Law (1945), pp. 517–518, 531, 532. For similar provisions in the Air Navigation Order, 1949, see ibid. (2nd ed. 1951), pp. 906–907, 950–951, 953. Concerning Hungarian law see below. Cf. the Swiss case of Bassanesi et al., Droit Aérien, 1931, pp. 777–788, and note 106 below. Unauthorized entry by air may be also treated, of course, as covered by provisions applicable to illegal crossings of frontiers in general. See note 30 above.

³⁴ For provisions in the British Air Navigation Order, 1923, see Shawcross and Beaumont, Air Law (1945), p. 565; they were substantially re-enacted in 1949, see ibid. (2nd ed., 1951), p. 965. For French law applying to prohibited areas in a state of siege see Le Goff, op. cit., at pp. 278–279, 776; for French practice during the Spanish Civil War see ibid., Supplement (1939), p. 128. See also Lemoine, Traité de Droit Aérien (1947), pp. 278, 809.

³⁵ For the practice in World War II, which has not been as well described or studied as that in World War I (see note 9 above), see 7 Hackworth, op. cit., at pp. 555–557; Zondag, op. cit., at pp. 71–75; Spaight, Air Power and War Rights (3rd ed., 1947), p. 424 et seq.; Netherlands Orange Book (1940), pp. 14–15; and note 36 below.

³⁶ See Deák and Jessup, A Collection of Neutrality Laws, Regulations and Treaties of Various Countries, Supplement (1940), pp. 124(1)–124(5), 278(3)–278(4), 823(8)–823(9). It is of interest that a Swedish prohibition of entry of foreign civil aircraft was not applicable to aircraft which might be in distress, but that Norway made no such express exception. Ibid., pp. 861(4), 988(4)–988(5).

³⁷ For two instances (Sweden and Turkey), see La Farge, The Eagle in the Egg (1949), pp. 180–190, 280, 287; and see, further, ibid., maps on end papers. For another instance (Ireland) see Lee, Operation Lifeline (1947), pp. 16, 91, and map on end papers. Cf. Arnold, Global Mission (1949), p. 204.

³⁸ Treaties and Other International Acts Series, No. 1591.

³⁹ Ibid., Art. 80.

⁴⁰ Art. 1.

⁴¹ Art. 3.

⁴² Arts. 5 and 6. A privilege of transit and non-traffic stop for aircraft on scheduled international air services is granted in the separate International Air Services Transit Agreement (Executive Agreement Series, No. 487; see also International Air Transport Agreement, ibid., No. 488).

⁴³ Art. 9. It has been suggested that this provision implies that the offending aircraft are not to be shot down except in case of resistance or attempted escape. Chauveau, Droit Aérien (1951), p. 49.

⁴⁴ See Arts. 5, 10, 11, 12, 13, 16, 68, Chicago Convention.

⁴⁵ Art. 27. Cf. Art. 18 of the Paris Convention.

⁴⁶ Art. 24.

⁴⁷ Art. 89.

⁴⁸ A Canadian draft contained provisions similar to those in the Paris Convention. See U. S. Department of State, Proceedings of the International Civil Aviation Conference (1948), Vol. 1, pp. 586–587.

⁴⁹ For some brief and general statements, see Oppenheim, International Law (7th ed., by Lauterpacht, 1948), Vol. 1, p. 762, note; Verdross, Völkerrecht (2nd ed., 1950), p. 181; Moreno Quintana and Bollini Shaw, Derecho International Público (1950), p. 248. Accioly, in a book published in 1946, merely cites the provisions of the Paris Convention, Tratado de Derecho International Público (1946), Vol. 2, pp. 288–289. The 1951 Soviet textbook, briefly reproduces the substance of the rules of the Paris Convention without citing the latter. Akademiya Nauk, op. cit., at pp. 318–319. Semble contra, Podestá Costa, op. cit., at p. 160. Cf. Meyer, op. cit., at pp. 284–285. See also note 28 above.

⁵⁰ Cf. U. S. Naval War College, International Law Documents 1948–49 (1950), p. 207, where the editor, referring to the Paris and Chicago Conventions, says: “Both Conventions leave in doubt the treatment to be accorded to foreign State aircraft forced by weather conditions or distress to fly over a State’s territory.”

⁵¹ See Art. 3.

⁵² Such aircraft, instead of being permitted to fly away, are sometimes returned by surface transport. For example, in July, 1951, two U. S. fighters which had lost their bearings and landed in Czechoslovakia were returned by truck, following the Telease of their pilots after nearly a month of detention and questioning. The Czechoslovak authorities said that the United States would be billed for hangar space and transportation. New York Times, July 4 to 6, 1951. In July, 1953, two Danish businessmen and their light plane were released by the Soviet authorities at the zonal border 48 hours after they had lost their way and landed in East Germany. New York Times, July 8, 1953.

⁵³ For the official documents see 15 Department of State Bulletin (1946) 415–419, 501–505, 544, 725, and New York Times, Sept. 4 and Oct. 10, 1946. For copious excerpts, see U. S. Naval War College, International Law Documents 1948–49 (1950), pp. 206–216.

⁵⁴ 15 Department of State Bulletin (1946) 502.

⁵⁵ Ibid. 504.

⁵⁶ Instructions to the American Ambassador in Belgrade, released to the press Aug. 20, 1946, ibid. 415–416.

⁵⁷ Acting Secretary of State to the Yugoslav Chargé d’Affaires, Aug. 21, 1946, ibid. 417–418.

⁵⁸ Same to same, Sept. 3, 1946, ibid. 504.

⁵⁹ Ibid,. 503.

⁶⁰ New York Times, Sept. 4, 1946.

⁶¹ 15 Department of State Bulletin (1946) 505.

⁶² New York Times, Oct. 10, 1946.

⁶³ 15 Department of State Bulletin (1946) 725.

⁶⁴ U. N. Press Release M/421, April 20, 1948. In November, 1951, it was reported that Yugoslavia apologized for forcing down a U. S. military aircraft, although the latter was outside the area in which American aircraft had been authorized to search for the lost C-47 subsequently reported to have landed in Hungary (note 91 below). New York Times, Nov. 23, 1951.

⁶⁵ As early as 1945 and 1946 the U. S. Navy Department protested as “hostile” the action of Soviet aircraft on two occasions in chasing off with gunfire U. S. naval aircraft which had entered by mistake the airspace above the Soviet-occupied Port Arthur-Dairen zone of Manchuria. In these incidents no damage was reported and in at least one of them the gunfire was apparently understood by the American naval authorities to have been of a warning character. See New York Times, March 2, 1946.

⁶⁶ 22 Department of State Bulletin (1950) 667–668, 753–754; New York Times, April 19, 1950.

⁶⁷ 25 Department of State Bulletin (1951) 909.

⁶⁸ New York Times, May 1, 1952. The French Government also lodged a separate protest on the diplomatic level. Id. See also ibid., April 30, 1952.

⁶⁹ The Soviet Union claims twelve miles as the width of its territorial waters in the Baltic Sea and elsewhere. This claim has not been recognized by Sweden, at least insofar as the Baltic is concerned.

⁷⁰ For the correspondence and related materials, see Sweden, Royal Ministry for Foreign Affairs, Documents Published by the Royal Ministry for Foreign Affairs, New Series II: 2, Stockholm 1952, Attacks Upon Two Swedish Aircraft over the Baltic in June 1952.

⁷¹ Ibid., p. 16.

⁷² Ibid., p. 28.

⁷³ Ibid., p. 39.

⁷⁴ Ibid., p. 16.

⁷⁵ Ibid., p. 31.

⁷⁶ 27 Department of State Bulletin (1952) 649–650; 28 ibid. (1953) 11–12; New York Times, Oct. 13 and 15, 1952, and Dec. 12, 1952.

⁷⁷ New York Times, Oct. 17, 1952.

⁷⁸ New York Times, March 11 to 17, and July 30, 1953; 28 Department of State Bulletin (1953) 474–475; 29 ibid. (1953) 180–183.

⁷⁹ New York Times, March 15, 1953; see also ibid., March 17, 1953.

⁸⁰ New York Times, March 13 to 18, 1953.

⁸¹ Parl. Debates, House of Commons, Daily Hansard, Vol. 512, No. 75, March 17, 1953, col. 2070.

⁸² New York Times, March 15, 1953.

⁸³ Ibid., March 20, 1953.

⁸⁴ Ibid., March 21, 25, 26, 30, and April 3, 8, 10, 13, 23, 1953.

⁸⁵ New York Times, March 18, 19, 24 and 25, 1953; 28 Department of State Bulletin (1953) 577–579.

⁸⁶ New York Times, March 19, 1953.

⁸⁷ New York Times, July 31, Aug. 1, 5 and 6, 1953; 29 Department of State Bulletin (1953) 179, 206–207. Does the Soviet mention of “proposing” that the American aircraft leave the Soviet airspace, rather than land as directed, indicate a change in the Soviet position on the proper treatment of intruding aircraft?

⁸⁸ By France, New York Times, May 11, 1952; by the United States, ibid., June 19, 1952.

⁸⁹ New York Times, Nov. 5, 1952, and Jan. 13, 14 and 17, 1953; 28 Department of State Bulletin (1953) 134. Cf. Time, Jan. 26, 1953, p. 35.

⁹⁰ Washington Evening Star and New York Times of Feb. 17, 1953.

⁹¹ 26 Department of State Bulletin (1952) 7, 128, 980–984; 28 ibid. (1953) 51–52, 257–259; New York Times, Dec. 3, 5, 7, 12, 22 to 30, 1951; Dec. 11 and 18, 1952; Jan. 24, Feb. 1 and 11, 1953. The incident was also discussed in the U.N. General Assembly. See General Assembly, 6th Sess., Official Records, Plenary Meetings, pp. 310–311, 313, See also note 92 below. Neither the U.S.S.R. nor Hungary is a party to the Chicago Convention.

⁹² U. S. Department of State, Text of Notes Presenting Formal Diplomatic Claima by the United States Against the Soviet and Hungarian Governments in the Case of the Four American Airmen and the C–17 Airplane 6026 Brought Down in Hungary on November 19, 1951 (presented and released March 17, 1953, summarized in 28 Department of State Bulletin (1953) 496).

⁹³ Ibid. 23.

⁹⁴ Ibid.

⁹⁵ Ibid. 24.

⁹⁶ Ibid. 28–30. Substantially similar assertions, to the extent they were applicable, were made in the note to the U.S.S.R.; the United States also denied the right of the Soviet Government to turn over the aircraft or the airmen to the Hungarian authorities. Ibid. 8–10. The treaty provisions cited in the note to Hungary do not appear to deal specifically with the treatment of intruding aircraft as such, but relate to human rights, treatment of nationals of the other contracting party, and consular functions and privileges.

⁹⁷ Ibid. 17. Emphasis inserted.

⁹⁸ See the views of the Permanent Court of International Justice in the Lotus Case, 1927, P.C.I.J., Series A, No. 10, p. 28, and of the International Court of Justice in the Asylum Case, I.C.J. Reports, 1950, pp. 266, 276–278, 286, and in the Case Concerning Rights of Nationals of the United States of America in Morocco, ibid., 1952, pp. 176, 199–201.

⁹⁹ See Art. 38 of the Statute of the International Court of Justice.

¹⁰⁰ In the Corfu Channel Case the International Court of Justice said that the obligation of the territorial sovereign to give notice of the presence of a minefield in his territorial waters was based, inter alia, on “elementary considerations of humanity, even more exacting in peace than in war.” I.C.J. Reports, 1949, p. 4, at p. 22.

¹⁰¹ It is hardly necessary to add that two or more states may by agreement provide for other and different standards to be applied in their mutual relations.

¹⁰² A few writers have discussed the existence of a right of “hot pursuit” of intruders which disobey orders to land. Kroell, op. cit., Vol. 1, at pp. 156–157; Accioly, op. cit., Vol. 2, at p. 177. The exercise of such a right might in some situations be the only effective remedy available to the territorial sovereign against a wilful intrusion for a hostile purpose such as photo-reconnaissance.

¹⁰³ In 1939 a Netherlands decree provided that intruding aircraft discovered by Netherlands military aircraft would be ordered by special signals to land and must obey the orders, but warned that the intruders would be exposed to serious risk since the giving of signals might not always be possible and “no warnings will as a rule be given by the anti-aircraft units.” Deák and Jessup, op. cit., Supplement (1940), pp. 823(8)–823(9).

¹⁰⁴ The killing of foreign nationals by border guards was a basis of awards by the U. S.-Mexican General Claims Commission under the Convention of Sept. 8, 1923, even where, as in the Garcia case, the killed person was illegally crossing the border and the guards had no other means of stopping him. In this case the Commission cited with approval the view that “human life may not be taken either for prevention or for repression, unless in cases of extreme necessity.” It noted that U. S. orders did not authorize firing on unarmed persons supposed to be engaged in smuggling or illegal crossing, and laid down the following principles: “In order to consider shooting on the border by armed officials of either Government (soldiers, river guards, custom guards) justified, a combination of four requirements would seem to be necessary: (a) the act of firing, always dangerous in itself, should not be indulged in unless the delinquency is sufficiently well stated; (b) it should not be indulged in unless the importance of preventing or repressing the delinquency by firing is in reasonable proportion to the danger arising from it to the lives of the culprits and other persons in their neighborhood; (c) it should not be indulged in whenever other practicable ways of preventing or repressing the delinquency might be available; (d) it should be done with sufficient precaution not to create unnecessary danger, unless it be the official’s intention to hit, wound, or kill. In no manner the Commission can endorse the conception that a use of firearms with distressing results is sufficiently excused by the fact that there exist prohibitive laws, that enforcement of these laws is necessary, and that the men who are instructed to enforce them are furnished with firearms.” United Nations, Eeports of International Arbitral Awards, Vol. 4, pp. 119, 121–122. See also the Swinney case, ibid., p. 98, and the Falcon case, ibid., p. 104, and the correspondence between the U. S. and Great Britain concerning the killing of Walter Smith and the wounding of Charles Dorseh on the Canadian border, resulting in the payment of an indemnity, Foreign Belations of the United States, 1915, pp. 414–423; but cf. the McMahan and Strickland cases, U. S.-Mexican General Claims Commission, United Nations, Reports of International Arbitral Awards, Vol. 4, pp. 486, 496. See also the I’m Alone case, in which an indemnity was in effect awarded for the intentional sinking by the U. S. Coast Guard after hot pursuit of a Canadian vessel suspected of rum-running when it apparently could not be overtaken and boarded. Ibid. Vol. 3, p. 1609; see also 2 Hackworth 703, and for amplification of the facts and discussion, this Journal, Vol. 23 (1929), p. 351, Vol. 29 (1935), pp. 296, 326; and Fitzmaurice in British Year Book of International Law, 1936, Vol. 17, p. 82. The same principle has been applied by international tribunals in cases involving the use of violence for the purpose of enforcing lawful orders, effecting arrests or quelling disturbances. See, in the U. S.Mexican General Claims Commission, the Roper, Brown and Small cases, United Nations, Reports of International Arbitral Awards, Vol. 4, pp. 145, 149, the Stephens case, ibid., p. 265, and the Kling case, ibid., p. 575. But cf. the Cadenhead case, American and British Claims Arbitration, Report of Fred K. Nielsen (1926), p. 505. Cf. also the award in the Naulilaa incident between Germany and Portugal, United Nations, Reports of International Arbitral Awards, Vol. 2, pp. 1011, 1025, and the Pugh case between Great Britain and Panama, ibid., Vol. 3, p. 1439. On the doctrine of abuse of rights in international law, see, in general, Lauterpacht, The Function of Law in the International Community (1933), pp. 286–306.

Cf. Cacopardo, Diritto Aeronautico di Guerra, pp. 47–48, 53.

¹⁰⁵ For analogous standards in maritime law, see Jessup, op. cit., note 2 above. By analogy with maritime law, aircraft under the control of unauthorized persons such as deserters, mutineers or thieves may be regarded as entitled to similar treatment, although such persons may not be. Aircraft flown by such persons to foreign states have been commonly returned in practice. See 22 Department of State Bulletin (1950) 595–599; New Tork Times, March 17, May 19, 20, 22, Sept. 25, 1953; Aviation Week, April 6, 1953, p. 7.

¹⁰⁶ The view that intrusions attributable to negligence may not be privileged is supported, inter alia, by the German cases cited in note 30 above, by the opinions of some writers (notably Fauchille and Oëx, note 5 above), and by statutory provisions such as Art. 88 of the Swiss Law on Air Navigation of Dec. 21, 1948, which penalizes flights in violation of a prohibition, whether the violation is intentional or due to negligence, Recueil des Lois Fédérales, 1950, Vol. I, pp. 491, 509; see also Riese and Lacour, Précis de Droit Aérien (1951), p. 320. It may be debatable, however, whether the test of negligence in such complicated and highly specialized procedures as air navigation should be relied upon as meaningful or just, unless the negligence is so evident as to amount to recklessness or constructive intent. Furthermore, distinction should, perhaps, be drawn between a mistake in geographical location or direction of flight on the one hand, and a mistake as to the legal situation of the intruder—for example, a mistaken belief that the entry has been authorized by the territorial sovereign—on the other hand.

Does the right of entry in distress imply a right to receive reasonable assistance through locally available facilities in locating an airfield and making the landing! Security considerations may lead to the withholding of such assistance in some situations. Cf. the difficulties reported to have been encountered by a British military aircraft in attempting an emergency landing at the Thule Air Force Base in Greenland, New York Times, Sept. 20, 1952.

¹⁰⁷ For an instance, see Arnold, Global Mission (1949), p. 204; cf. the incident at Thule, cited above, note 106.