A basic assumption of the international system is that sovereignty—plenary power over territory—inheres individually in each state which has the better claim to title over that territory, and that it is not shared. But this is an assumption; from a legal point of view it may even be a presumption: it is not a rule, still less a peremptory norm. There is nothing to prevent a state from freely abandoning its sovereignty in favour of merger in another state, and what can be done in whole can be done in part. Groups of states, or an international organization, can come to exercise dispositive authority over a given territory: questions may then arise as to the modalities of the exercise of such powers and their relation to the self-determination of the people of the territory concerned. Some of these situations are grouped for consideration here.

(A)  Agreement between the States Concerned

A cession of territory may depend on the political decision of the states concerned in a dispute. Such a cession may be the result of a political claim, on grounds of history or security, a legal claim, or a combination of these. The conditions under which transfer occurs may be influenced by the recommendations of political organs of international organizations and, latterly, by the principle of self-determination (see chapters 5, 29). On numerous occasions, plebiscites have been organized under the auspices of the United Nations, with the results treated as indicative or binding.2

(p. 246) (B)  Joint Decision of the Principal Powers

Likewise on a number of occasions a group of leading powers, perhaps in association with a number of other states, have assumed a power of disposition, although the legal bases of such a power were sometimes problematic.3 It is possible that, as in the case of the creation of a new constitution by rebellion, the political and legal bases are inseparable: certainly the legal consequences of this power of disposition are commonly accepted. The mandates system rested in substantial part at least on such a power of disposition, and the International Court accepted its consequences in its successive advisory opinions on the status of South West Africa.4

Disposition of territory alone is not enough for a transfer of sovereignty, however. In the Eritrea/Yemen arbitration, the Tribunal considered the status of certain Red Sea islands in light of Article 16 of the Treaty of Lausanne, by which the Ottoman Empire renounced sovereignty over the islands. It held that no doctrine of reversion of historical title applied, so that sovereignty over the islands in question had remained indeterminate after Turkey divested itself of the territory.5 What was required for acquisition of the territory was ‘an intentional display of power and authority over the territory, by the exercise of jurisdiction and state functions, on a continuous and peaceful basis’.6

(C)  Action by United Nations Organs

It is doubtful if the UN has a capacity to convey title, in part because it cannot assume the role of territorial sovereign: in spite of the principle of implied powers, the UN is not a state and the General Assembly only has a power of recommendation. On this basis it can be argued that GA Resolution 181(II) of 29 November 1947, approving a partition plan for Palestine, was if not ultra vires at any rate not binding on member states.7

However this may be, the fact is that states may agree to delegate a power of disposition to a political organ of the UN, at least where the previous sovereign has relinquished title; but there is no transfer of sovereignty and no disposition of a title inhering in the Organization. In such cases the Organization acts primarily as a referee. The General Assembly played this type of role in relation to the creation of the new states of Libya and Somalia and in the case of territory relinquished by Italy under the Peace Treaty of 1947.8

References(p. 247) On similar principles, the General Assembly probably retained a power to terminate trusteeship status for cause.9 But the termination of mandates was a matter of more difficulty, partly because the power of disposition arguably inhered in the principal Allied Powers participating in the Treaty of Versailles.10 It may be that, in the historic cases of mandate and trusteeship, and also of the few remaining territories to which Chapter XI of the Charter applies, the UN does not ‘confer sovereignty’, but rather decides on or approves the manner in which the principle of self-determination is to be implemented. Certainly resolutions of the General Assembly play an important element in the consolidation of title over territory. This is especially the case with the resolutions based on Resolution 1514(XV), the Declaration on the Granting of Independence to Colonial Countries and Peoples.11

However that may be, the General Assembly assumed the power to terminate the Mandate for South West Africa in Resolution 2145(XXI) of 27 October 1966.12 Subsequently the General Assembly established the Council for South West Africa, appointed a UN Commissioner to administer the territory, and renamed the territory ‘Namibia’. South Africa failed to respond to these developments and the Security Council adopted resolutions in 1969 and 1970 ‘recognizing’ the decision of the General Assembly to terminate the Mandate and calling upon all states to take measures to implement the finding that South Africa’s continued presence in Namibia was illegal. By a further resolution the International Court was asked to give an advisory opinion on the question, ‘What are the legal consequences for States of the continued presence of South Africa in Namibia notwithstanding Security Council Resolution 276 (1970)?’ As a preliminary to giving its views on the substance of the question, the Court considered the validity of GA Resolution 2145(XXI) in terms of the Charter.13 The Court held that the power of the League of Nations, and therefore of the United Nations, to revoke the Mandate for reasons recognized by general international law (termination on the ground of material breach of a treaty) was to be implied.14 The role adopted by the General Assembly, assisted by the Security Council, was to take such action as was necessary to ensure the application of the provisions of Resolution 1514(XV) to the people of Namibia. In formal terms at least, this did not involve a power of disposition as such, but the application of the provisions of the Charter, as interpreted by the practice of the organs, relating to the principle of selfReferences(p. 248) determination.15 Namibia eventually achieved independence in 1990 aft er elections supervised by the UN Transition Assistance Group.16

The role of the General Assembly in the decolonization of Western Sahara has involved a complex of issues concerning the principle of self-determination and the legal interests of Morocco (and at one time Mauritania).17The situation remains unresolved.18

In the aftermath of the Iraqi invasion and occupation of Kuwait the Security Council adopted Resolution 687 (1991). The resolution specified the measures to be taken under Chapter VII of the Charter. In particular, the Security Council demanded respect for the agreed territorial delimitation,19 and decided ‘to guarantee the inviolability of the…international boundary and to take as appropriate all necessary measures to that end in accordance with the Charter of the United Nations’. In the event, following the eviction of Iraq by a broad-based coalition acting under a Security Council mandate, a Demarcation Commission was created: it submitted a Final Report on the demarcation of the international boundary between Iraq and Kuwait on 20 May 1993.20 In Resolution 833 (1993) the Security Council adopted the decisions of the Commission as ‘final’. The exercise was, at least in form, the demarcation of an already agreed alignment and no ‘reallocation’ was intended. However, when the Final Report is examined it follows almost inexorably that elements of delimitation were involved, especially in relation to the maritime delimitation.21 The outcome was controversial but it is important to remember that the Security Council expressly disclaimed an intention to use the demarcation process for the purpose of ‘reallocating territory between Kuwait and Iraq’. Iraq subsequently recognized the boundary so determined.22

In the context of maintaining international peace and security UN organs have also been prepared to assume administrative functions in relation, for example, to theReferences(p. 249) City of Jerusalem,23 the Free City of Trieste,24 East Timor,25 and Kosovo.26 The existence of such administrative powers rests legitimately on the principle of necessary implication and is not incompatible with the view that the UN cannot have territorial sovereignty.

Although an undivided sovereignty is the normal mode of territorial administration, exceptional situations exist which cannot be forced into the sovereignty straightjacket. Thus sovereignty may be held jointly by two states, as in a condominium,27 or distributed in time, as with a leasehold or other grant of sovereign rights subject to an ultimate right of reversion.28 Or it may be in abeyance, as with the mandate and trusteeship systems.29 A brief analysis of some other possibilities follows.

(A)  Territory Sub Iudice

When a territorial dispute is referred to adjudication, there is a real sense in which sovereignty is in abeyance pendente lite: at any rate the tribunal cannot acknowledge either state as sovereign pending its decision, although the decision once given will be declaratory in form. The analogy here is perhaps with the right of possession which the sequester or stakeholder had in Roman law.30 The existing regime rests on acts in the law which in principle could not create sovereignty in the existing holder but which do not render the region terranullius. For practical purposes the present possessor may be regarded as exercising normal powers of jurisdiction and administration, subject only to external limitations arising from the legal instruments determining the status of the region. Thus the relevant agreement may contain provisions for demilitarization.

Furthermore, there must be an implied obligation not to act in such a way as to render fulfilment of the ultimate objective of the arrangement impossible. Thus if theReferences(p. 250) stated objective is to provide for an expression of opinion by certain minority groups it would be ultra vires to deport or to harass and blackmail the groups concerned.31 In this respect, the absence of a textually-prescribed enforcement mechanism is not enough to offset the obligation not to impede fulfilment of the end goal, though the presence of such a mechanism will add yet another arrow to the bow. The status of the inhabitants in terms of nationality and citizenship will depend on the circumstances of the particular case.32 If one accepts the obligations inherent in the doctrine of the ultimate objective then the conferment and deprivation of nationality would not be a matter of domestic jurisdiction for the administering state.