Jump to Content Jump to Main Navigation
Oppenheim's International Law - Volume 1 Peace, 9th Edition edited by Jennings, Robert; Watts KCMG QC, Arthur (19th June 2008)

Part 2 The objects of international law, Ch.5 State territory, Subjugation

Sir Robert Jennings qc, Sir Arthur Watts kcmg qc

From: Oppenheim's International Law: Volume 1 Peace (9th Edition)

Edited By: Robert Jennings, Arthur Watts KCMG QC

From: Oxford Public International Law (http://opil.ouplaw.com). (c) Oxford University Press, 2015. All Rights Reserved. Subscriber: null; date: 14 November 2019

Territory, acquisition and transfer — Territory, title — Belligerents — Occupation — Use of force, threat


Phillipson, Termination of War and Treaties of Peace (1916) Schätzel, Die Annexion im Völkerrecht (1921) Fabbri, Effetti giuridici delle annessioni territoriale (1931) McMahon, Conquest and Modern International Law (1940) Bentivoglio, De ballatio nel diritto internazionale (1948) Fischer Williams, BY, 7 (1926), pp 22–42 Udina, Rivista, 22 (1930), pp 301–41 Schätzel, Archiv des Völkerrechts, 2 (1949), pp 1–28 de Visscher, Problèmes de confins en droit international public (1969), pp 181ff Jennings, The Acquisition of Territory in International Law (1963), ch IV Brownlie, International Law and the Use of Force by States (1963) Schwebel, AJ, 64 (1970), pp 344–47; Schwarzenberger, International Law (vol 2, 1968), see pt 4 for the law of belligerent occupation.

§ 263  Concepts of conquest and subjugation

Subjugation, that is the acquisition of territory by conquest followed by annexation, and often called title by conquest, had to be accepted into the scheme of modes of acquisition of title to territorial sovereignty in the period when the making of war was recognised as a (p. 699) sovereign right, and war was not illegal. Simple title by subjugation has always been relatively rare, because victors more usually enforced a treaty of cession. In any event, war waged for the purpose of the acquisition of territory has probably been unlawful since Article 10 of the League of Nations Covenant.1 Yet though subjugation is obsolescent, it is still necessary to describe briefly its legal limitations, if only because a root of title is to be judged by the law as it was when the relevant facts arose. Were it otherwise, ancient and otherwise stable titles might for ever be open to question.

At no period did conquest alone and ipso facto make the conquering state the territorial sovereign of the conquered territory, even though such territory came through conquest for the time being under the sway of the conqueror. Conquest was a mode of acquisition only if the conqueror, after having firmly established the conquest, and the state of war having come to an end, then formally annexed the territory.2 If a belligerent conquered part of the enemy territory and afterwards made the vanquished state cede the conquered territory in the treaty of peace the mode of acquisition was not subjugation but cession.3 Such a treaty of cession, however, would now be qualified by Article 52 of the Vienna Convention on the Law of Treaties, which provides that: ‘A treaty is void if its conclusion has been procured by the threat or use of force in violation of the principles of international law embodied in the Charter of the United Nations’.4

§ 264  Germany after the Second World War

The legal status of Germany after her unconditional surrender at the end of the Second World War illustrates the distinction between simple conquest and subjugation. After the unconditional surrender of the German forces and the abolition of what purported to be the German Government, Great Britain, the United States of America, Russia, and France, in a joint Declaration issued on 5 June 1945, assumed ‘supreme authority’ with respect to Germany. It was expressly stated that the assumption of these powers did not effect the annexation of Germany and that (p. 700) her future boundaries and status would be determined by the four states issuing the Declaration. But for that disclaimer of the intention of annexation the assumption of full authority over Germany would have been indistinguishable from subjugation.1 Nevertheless, the international personality of Germany became suspended, and the exercise of the internal and external prerogatives and rights of the German State was vested either jointly with the Four Powers or with any one of them in respect of the part of German territory placed under its administration. In due course the Federal Republic of Germany and the German Democratic Republic were established on the territory of the German State, although vestiges of the Four Powers’ original status as occupants remained until renounced pursuant to agreements reached in 1990.2

§ 265  Subjugation distinguished from belligerent occupation

It must be emphasised that subjugation was, even prior to changes in the lawfulness of the use of force or threat of force, recognised as being wholly different from forcibly taking possession of territory during the continuance of war. Such an occupation, whatever the ultimate ambition of the conqueror, did not confer a title so long as the war was not terminated (debellatio) either through simple cessation of hostilities or by a treaty of peace.1 Therefore, the practice, which has sometimes prevailed, of purporting to annex during a war an occupied part of enemy territory was unlawful and invalid. Indeed the law of war itself clearly provides that the belligerent occupier does not enjoy sovereignty.2

§ 266  Consequences of subjugation

Although subjugation is an original mode of acquisition, since the sovereignty of the acquiring state is not derived from that of the state formerly sovereign of the territory, the new sovereign is nevertheless the successor of the former as regards many matters already discussed under the topic of state succession.1 As regards the national status of the subjects of the subjugated state, doctrine and practice agreed that those domiciled on the annexed territory of a state which ceased to exist, and remaining (p. 701) there after annexation became ipso facto by the subjugation2 subjects of the subjugating state. But, the national status of subjects of the annexed state who are domiciled abroad and do not return, and further of such as have left the country before the annexation or immediately afterwards, has been disputed.3 Probably a distinction must be made between those individuals leaving the country before and those leaving it after annexation.4 The former are not under the sway of the subjugating state at the time of annexation, and, since the personal supremacy of their home state terminates with its extinction through annexation, they would seem to be outside the sovereignty of the subjugating state. But those individuals who have left the country after annexation have left it at a time when they had already become subjects of the new sovereign, and they therefore remained such subjects even after they had left the country.5

(p. 702) § 267  Veto of third states

In international law as it obtained prior to the Covenant of the League, the Charter of the United Nations, and the General Treaty for the Renunciation of War the legal position with regard to the veto of third Powers could be summarised as follows:

Although subjugation was an original mode of acquiring territory, and no third state had as a rule1 a right of intervention, the conqueror had not even then an unlimited possibility of annexing the territory of the vanquished state. When the balance of power was endangered, or when other vital interests were at stake, third states could and might intervene, and history records many instances of such interventions. But the validity of the title of the subjugating state did not depend upon recognition on the part of other states; nor was mere protest of a third state then of legal weight. The position has now changed as the result of the developments in international law about the use of force or threat of force; and recognition, or non-recognition, on the part of third states, or indeed the United Nations, may now be of even decisive importance. On the other hand, a title by conquest necessarily retains an element of validity in those cases where the root of present title goes back to the time when title by subjugation was recognised in international law.

§ 268  Renunciation of force or threat of force and title to territory

The place of force in the law has been changed successively and cumulatively by Article 10 of the League of Nations Covenant, by the General Treaty for the Renunciation of War of 1928, by the United Nations Charter;1 by parallel changes in customary law;2 and by the Declaration on Friendly Relations,3 which makes particular provision in regard to territorial acquisition in the following terms:

‘The territory of a State shall not be the object of military occupation resulting from the use of force in contravention of the provisions of the Charter. The territory of a State shall not be the object of acquisition by another State resulting from the threat or use of force. No territorial acquisition resulting from the threat or use of force shall be recognized as legal. Nothing in the foregoing shall be construed as affecting.

(a)  Provisions of the Charter or any international agreement prior to the Charter regime and valid under international law; or

(b)  The powers of the Security Council under the Charter.’

These changes in the law have been reflected in decisions of the United Nations organs. Thus UN Security Council Resolution 242 of 24 October 1970, dealing with the situation in the Middle East, and which inter alia emphasised ‘the inadmissibility of the acquisition of territory by war …’ and UN General (p. 703) Assembly Resolution 2949 of 8 December 1972, also reaffirms ‘that the territory of a State shall not be the object of occupation or acquisition by another State resulting from the threat or use of force’. The provision of Article 52 of the Vienna Convention on the Law of Treaties, pronouncing void any treaty imposed by unlawful force, has already been noted.4

It will be noted that these instruments are not in the like terms, and that whereas the earlier ones seek to deny title acquired by certain kinds of armed force — for example armed force used in contravention of the United Nations Charter, thus leaving aside the consequences of forcible self-defence — the later resolutions seem to reject the possibility of acquiring title to territory by military force or threat of force in quite general terms. It is necessary to try to assess the effect of reiterated, though differing, pronouncements about the legal consequences of force, in a world in which the use of force or threat of force is commonplace and in which force or threat of force inevitably produces some consequences which the law cannot simply ignore.5

Of the many legal questions raised by the use of armed force the one relevant to this chapter is whether a state can now claim a new title to sovereignty by purporting to annex a territory reduced by the employment of, or threat of, armed force? The answer to that question is without doubt in the negative. It is, indeed, directly answered by the Declaration on Friendly Relations: ‘The territory of a State shall not be the object of acquisition by another State resulting from the threat or use of force’. As to the conquest disguised as a cession, the question of the legal status of a treaty imposed by duress has been dealt with by the Vienna Convention, Article 52;6 so the purported cession, and any claim to an alternative title by subjugation, will both be invalid.

Yet not every use of force or threat of force is unlawful, and a problem remains concerning the possible consequences of the unlawful use of force, or threat of force, notably the ‘inherent right of individual or collective self-defence if an armed attack occurs against a Member of the United Nations’, provided for in Article 51 of the United Nations Charter. What then is the position of territory occupied in the course of an operation of self-defence? To do more than to note this problem would be to enter upon the large questions of lawful and unlawful use or threat of force, and open the scope and limits of self-defence; matters not within the scope of the present volume.7

(p. 704) The only question relevant to entitlement to territorial sovereignty is: can the reduction of a territory in the course of the lawful use of force in self-defence, be followed by a purported annexation of that territory, creating per se and ipso facto a valid title to permanent territorial sovereignty? The answer to that question8 must surely now be in the negative.

There is, however, a further dimension of this problem to be considered. There is impressive authority for the view that the prohibition of force expressed in Article 2, paragraph 4, of the Charter of the United Nations is ‘not only a principle of customary international law but also a fundamental or cardinal principal of such law’; and indeed that it has the character of ius cogens.9 If the rule against the use of force is of this peremptory character, the question then must arise whether it is now still permissible to plead even an ancient and historic title by subjugation; and this notwithstanding the principle of the inter-temporal law which, though in a sense axiomatic, is nevertheless not one which has attracted the notion of a ius cogens. In this sort of situation it is important to distinguish between an historic origin and root of title, and the possible later claims to title, title which may flow from recognition, acquiescence, and general historical consolidation, and which may lend legitimacy to ‘a continuous and (p. 705) peaceful display of territorial sovereignty’,10 even if the original claim now appears vitiated in the light of this peremptory norm prohibiting its acquisition by force or threat of force. This conclusion is fortified by the principle of stability which must be at least a significant factor in questions concerning territorial sovereignty.11

These considerations, however, affect more than historic titles. The rule that a state may not now claim a new territorial title by reason of subjugation, possibly falls short of preventing such a state, after a considerable period of peaceable possession and administration, and possibly indeed with the acquiescence of the former sovereign, from being able to claim a title by historical consolidation, with such elements as general recognition, lack of protest, and the like. It appears at any rate a doubtful question whether the law, even in ius cogens, goes so far as to infect with nullity another subsequent title to the territory, if such a title be otherwise and independently established; though no doubt that is arguable. But the situation where the status quo ante cannot be restored in its entirety, is one familiar in all systems of law and with which they have to cope. The law often has to take some account of consequences of situations brought about unlawfully, even indeed the results of acts which the law regards as null, or from agreements or decisions which are in law ‘void’ or ‘voidable’.12


See Brownlie, International Law and the Use of Force by States (1963), p 217.

See Hurst, BY, 5 (1924), pp 163–178. See Re Southern Rhodesia [1919] AC, at pp 239, 240 as to the position between the annexing state and its own subjects; and also Sobhuza II v Miller [1926] AC 518. For a clear statement that unilateral annexation of part of territory without the consent of the state concerned is now invalid see the decision of the Belgian Court of Cassation of 16 June 1947, in Re Bindels, Journal des Tribunaux, 62 (1947), p 511.

See § 244. Annexation by a state of territory hitherto under its administration, or leased to it, or granted to it for its ‘use, occupation, and control’ (see § 170), is not subjugation, because the annexing state was already exercising sovereignty over the territory in question. Examples of annexations of this kind were the annexation by Austria in 1908 of the Turkish provinces of Bosnia and Herzegovina, and of the Turkish island of Ada-Kalé in the Danube in 1913 (these territories having been under its administration since 1878), and the annexation by Great Britain immediately after the outbreak of war with Turkey in 1914 of the island of Cyprus which had been under British administration since 1878. Turkey, however, by the Treaty of Lausanne 1923, Art 20, recognised ‘the annexation of Cyprus proclaimed by the British Government on 5 November 1914’. Such annexations without the consent of the state which in law owns the territory were probably always legally flawed; apart from the possible effects of subsequent recognition from other states, or of acquiescence. See also the International Status of South-West Africa case, ICJ Rep, 1950, p 128; and § 88.

See also § 268.

Unconditional Surrender of Germany. Declaration and Other Documents (Cmd 6648 (1945); and see for this question generally, pp 135–7; see also notes on pp 568–69 of the 8th ed of this vol.

See ILM, 5 (1990), pp 1077–93.

On the vexed question of the territory forcibly occupied by Israel, see § 268, n 7.

See vol II of this work (7th ed), § 60, and Lindley, pp 161–64. For this reason the annexation of the Orange Free State in May 1900 and of the South African Republic in September 1900, by Great Britain during the Boer War, was premature. So also was the annexation of Tripoli and Cyrenaica by Italy during the Turco-Italian War in November 1911 and, again, the annexation of Ethiopia by Italy in 1936. As to the purported annexation of Abyssinia by Italy on 9 May 1936, see Strupp, RG, 44 (1937), pp 44–46; see also Sereni, Rivista, 15 (1936), pp 404–33, and ZöR, 17 (1937), pp 287–313; Nostitz-Wallwitz, ZöV, 7 (1937), pp 38–46; Rousseau, RG, 44 (1937), pp 5–42, 162–198. On the applicability of multilateral conventions to occupied territories, see Meron, AJ, 72 (1978), pp 542–57; and on the exploitation of the resources, see Clagett and Johnson, ibid, pp 558–85; also Proceedings of the American Society of International Law, 72 mtg (1978), pp 118ff.

See § 60.

See Campbell v Hall (1774) 1 Cowper 208, and United States v Repentigny (1866) 5 Wallace 211. The case is similar to that of cession, see Keith, The Theory of State Succession (1907), pp 45 and 48; Moore, iii, § 379; and especially O’Connell, State Succession in Municipal Law and International Law (vol 2, 1967), ch 2, with many examples of annexation and cession. As to the meaning of the term ‘established’ in a treaty for the exchange of populations see Advisory Opinion of the Permanent Court on the Exchange of Greek and Turkish Populations, PCIJ, Series B, No 10. As to the meaning of domicile see award of Kaeckenbeeck noted by Garner in AJ, 20 (1926), pp 130–35. As to the meaning of the terms ‘resident’ and ‘ordinarily resident’ in a British Order in Council defining the national status of the inhabitants of Cyprus after the British annexation in 1914, see Gout v Cimitian [1922] 1 AC 105.

This statement in the main text was left unqualified in the 8th ed of this work but there is also a view that persons in this position might be given an option at any rate if they are ready to leave the country. See McNair, Opinions, ii, pp 3–28; Parry, Nationality and Citizenship Laws of the Commonwealth and Ireland (1957), pp 274–5; Weis, Nationality and Statelessness in International Law, pp 149, and 153–4; Mervyn Jones, British Nationality Law (1956), pp 20–26; Whiteman, Digest, 8, pp 104–12; Ginsburg in Res Baltica (1968), pp 160–90.

See R v Home Secretary, ex parte L [1945] 1 KB 7; Stoeck v Public Trustee [1921] 2 Ch 67; Re Chamberlain’s Settlement [1921] 2 Ch 533, and cf USA ex Rel Schwarzkopf (1943) 137 Fed 2nd. See also Mervyn Jones, British Nationality and Practice (1947), pp 39–56; and revised ed (1956), also pp 18–22, though the treatment is somewhat different; and Weis, Nationality and Statelessness (1956), ch 11; Grampner, LQR, 61 (1945), pp 161–78. As to the treatment of such persons by the Treaty of Lausanne 1923, see Bentwich, BY, 7 (1926), pp 97–109. As to purported conferment of German nationality on ethnic Germans in Moravia and Bohemia, see § 55, n 6, § 391, n 28.

Yet in the case of Count Platen-Hallermund, a Cabinet Minister of King George V of Hanover, who left Hanover with his King before the annexation in 1866 and was in 1868 prosecuted for high treason before the Supreme Prussian Court at Berlin, this Court decided that the accused had become a Prussian subject through the annexation of Hanover. See Halleck, International Law (1878), ii, p 150, on the one hand, and, on the other, Rivier, ii, p 436. Valuable opinions of Zachariae and Neumann, who deny that Count Platen was a Prussian subject, are printed in Deutsche Strafrechts-Zeitung (1868), pp 304–20. See also Schoenborn, Strupp, Wört, ii, p 271, and Borchard, AJ, 37 (1943), pp 634–40; Murray v Parkes [1942] 2 KB 123.

Supposing their original home state is extinguished as the result of the war (as in the case of the Orange Free State and the South African Republic), do they become stateless? In the Draft Convention on Elimination of Statelessness prepared in 1954 by the ILC it is laid down that in the absence of treaty provisions preventing statelessness in connection with changes of territory, states to which territory is transferred, or which otherwise acquire territory, shall confer their nationality upon the inhabitants of such territory unless such persons retain their former nationality by option or otherwise or unless they have or acquire another nationality. See also, Jellinek, Der automatische Erwerb und Verlust der Staatsangehörigkeit durch völkerrechtliche Vorgänge (1951); Sibert, Traité de droit international public (2 vols, 1951), pp 543–47.

But this rule had exceptions, as in the case of a state whose independence and integrity have been guaranteed by one or more states.

See Art 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’; see also Art 51, saving ‘the inherent right of individual or collective self-defence if an armed attack occurs against a Member of the United Nations, until the Security Council has taken measures necessary to maintain international peace and security’.

See Brownlie, International Law and the Use of Force (1963). See also §§ 54–5 on non-recognition.

GA Res 2625 (XXV) (1970).

See § 245.

On the illegality of the use of force, see generally the Judgment of the ICJ in Case concerning Military and Paramilitary Activities in and against Nicaragua, ICJ Rep (1986), p 14 especially paras 172ff for customary law; but title to territory was not an issue in that case.

See also McNair, Treaties, p 210. It should perhaps be said again that this is not to call in question titles first established under an older and different law; not only because of the principle of inter-temporal law but also because of the principle of stability which underlies all matters of territorial title. Further what is now rejected is title by subjugation, ie completed military conquest. Other kinds of pressure, eg economic pressures, raise quite other issues.

No attempt, therefore, is made here to decide upon the rights of a belligerent occupant of enemy territory; nor the results of the several other kinds of occupation in which a state participating in hostilities of one kind or another may find itself involved; nor yet what has been called ‘post-surrender occupation’. See eg Gerson, Israel, the West Bank and International Law (1978), p 5. These questions relate in large part not so much to the law of acquisition or loss of territory, as to the law governing the conduct of hostilities, which is dealt with in vol II of this work. It may be useful, however, to note here part of the considerable literature on these matters that the conflicts in the Middle East have produced: Cattan, Palestine, the Arabs and Israel (1969); Gerson, Harv ILJ, 14 (1973), pp 1–49; Cattan, Palestine and International Law (2nd ed, 1976); George, Israeli Occupation, International Law and Political Realities (1980); Feinstein, Israel Law Rev, 2 (1976), pp 516–62; Kuttner, Israel Year Book of Human Rights, 7 (1977) pp 166–221; Martin, Le Conflict Israelo-Arabe (1973); Craen, Revue Belge, xiv (1978–79), i, pp 500–38; and see Moore (ed), The Arab-Israeli Conflict (3 vols, 1974), Passim. On the Camp David Agreement of 17 September 1978, see Le Morzellec, AFDI (1980), pp 175–92.

It should be added that UN GA Res 2949 of 8 December 1972, affirmed that ‘changes in the physical character or demographic composition of occupied territories are contrary to the purposes and principles of the Charter of the United Nations, as well as to the provisions of the relevant international conventions’.

On this whole question see Judge Schwebel’s comment, ‘What Weight to Conquest’, in AJ, 64 (1970), pp 344–47; also see Norton Moore, AJ, 77 (1983), p 610. Judge Schwebel, though approaching the point more than once, stops short of saying that the successful user of lawful force may claim an incidental conquest and occupation of territory as being of itself a good title to territorial sovereignty over that territory.

Judge Schwebel, however, cites with approval E Lauterpacht, Jerusalem and the Holy Places (1968), at p 52, where he says, ‘territorial change cannot properly take place as a result of the unlawful use of force. But to omit the word unlawful is to change the substantive content of the rule and to turn an important safeguard of legal principle into an aggressor’s charter. For if force can never be used to effect lawful territorial change, then, if territory has once changed hands as a result of the unlawful use of force, the illegitimacy of the position thus established is sterilized by the prohibition upon the use of force to restore the lawful sovereign. This cannot be regarded as reasonable or correct.’ This, however, with respect, is to confuse the question of when force may lawfully be used, inter alia over the possession of territory, and the quite different question whether a resulting territorial conquest can of itself be pleaded as creating a title to the territory. He who resorts to lawful self-help to recover what is in law his own would hardly thereafter plead the forcible repossession as being itself a sufficient title to ownership. In the Falklands War of 1982, first Argentina and then the UK successively took the islands by force. But although the principal question at issue was the rightful title to sovereignty over the islands, neither party pleaded, nor presumably would even have thought of pleading that they had acquired a new title by conquest. On the whole Falklands (Malvinas) question see Beck, The Falkland Islands as an International Problem (1988).

Case concerning Military and Paramilitary Activities in and against Nicaragua, ICJ Rep (1986), 14, para 189.

10  Island of Palmas case, see § 273. For instances of Goa and of West Irian and of Kuwait, see § 275, n 1.

11  See Fitzmaurice, Third Report to the ILC on the Law of Treaties, UN Doc A/CN 4/115 of 18 March 1958, at para 62.

12  See also essays by E Lauterpacht, and by Jennings in Cambridge Essays in International Law (1965). Lauterpacht cites inter alia Art 174 of the Treaty establishing the European Economic Community:

‘If the Court of Justice considers the complaint well-founded, it shall declare the measure concerned null and void.

Provided always that if the Court declares a regulation null and void, it shall, if it considers this necessary, declare which effects of the null regulation shall be deemed to remain in force.’