Cross-border unitization and joint development agreements: an international law perspective.

International custom has historically been the core source of international law, and has remained so in some areas of the law despite efforts of codification and creation of multilateral treaties in important subjects. (23) International custom derives its force from two essential elements: the concurrence of uniform state practice and a subjective belief that adherence to these rules is obligatory (opinio juris). (24) Actual state practice is the basis for customary law; this can also be found in the writings of learned international lawyers and in judicial decisions of national and international courts. (25) Resolutions of the United Nations General Assembly (UNGA) can be evidence of customary law as they reflect the views of the majority of member states. (26) Their normative value might be determined, inter alia, on the basis of their general acceptance. (27)

It is important to note that the decisions of the ICJ are "not governed by the principle of stare decisis." (28) Article 59 of the Statute of the ICJ states that Court decisions are not binding except between the parties to a case and in connection to that particular case only. (29) However, this does not mean that the Court ignores precedent. As quoted above, Article 38 (1)(d) of the Statute of the ICJ requires the Court to apply judicial decisions, subject to the provisions of Article 59, as a "subsidiary means" for the determination of rules of law. (30) It uses precedent as a persuasive argument rather than a binding one. From a practical standpoint, if the Court does not follow previous case precedent in rendering a decision, then those prior cases are likely to be distinguished from the case currently before the Court. (31)

B. Sovereignty, Territory, and Boundaries

Sovereignty, territory, and boundaries are key concepts of public international law. They define essential attributes of a state, the primary subject of international law. (32) Sovereignty represents "the basic constitutional doctrine of the law of nations, which governs a community consisting primarily of states having a uniform legal personality." (33) Sovereignty means that states have "1) jurisdiction, prima facie exclusive, over a territory and the permanent population living there; 2) a duty of non-intervention in the area of exclusive jurisdiction of other States; and 3)the dependence of obligations arising from customary law and treaties on the consent of the obligor." (34) Furthermore, "[t]he territorial sovereignty of states extends to the mineral resources in the soil and subsoil of their land territory and territorial sea to an unlimited depth." (35) States have exclusive sovereign rights rather than full territorial sovereignty over mineral resources located in the continental shelf. (36) Sovereign rights of a coastal state for the purpose of exploring and exploiting the natural resources extend to the EEZ. (37)

Territorial integrity is a "necessary corollary to the principle of territorial sovereignty." (38) It protects the sanctity of a state's territory from unauthorized invasion or interference from operations conducted in another state. (39) It follows that no state may exercise rights over mineral resources of other states without their consent. (40)

The fundamental principle is that territorial sovereignty of states does not extend beyond their borders; each state exercises exclusive authority on its own territory and any infringement across an international boundary would constitute a violation of another state's territorial sovereignty or exclusive sovereign rights. (41)

II. DELIMITATION OF INTERNATIONAL MARITIME BOUNDARIES

"Maritime boundary delimitation is as old as the concept of offshore jurisdiction itself." (42) Subsurface petroleum deposits located offshore pose a set of problems that usually concern the delimitation of the boundaries of the continental shelf and the EEZ between the bordering states. (43)

A. Delimitation of the Continental Shelf

"The concept of national jurisdiction over a continental shelf beyond the territorial sea is relatively modern in origin, usually being traced to the 1945 Truman Proclamation." (44) The 1940s and 1950s saw pressures on the legal structure that previously had recognized only the three mile territorial sea limit, and even that was not universally accepted. (45) Coastal states became interested in gaining control over an extended area of the sea and its resources. (46) The Truman Declaration of 1945 was a major influence in boundary delimitation. The Truman Declaration proclaimed, "[T]he Government of the United States regards the natural resources of the subsoil and sea bed of the continental shelf beneath the high seas but contiguous to the coast of the United States as appertaining to the United States, subject to its jurisdiction and control." (47) Because of the likely existence of oil resources, it also included a provision, that "[w]here the continental shelf extends to the shores of another State ... the boundary shall be determined by the United States and the State concerned in accordance with equitable principles." (48)

The 1958 Geneva Convention on the Continental Shelf (49) seemed to depart from the principles of the Truman Declaration. Instead, following deliberations by the International Law Commission (ILC) that examined several methods of delimitation, the Geneva Convention stated:

In the absence of agreement, and unless another

boundary line is justified by special circumstances, the

boundary [between adjacent nations] shall be

determined by application of the principle of

equidistance from the nearest points of the baselines

from which the breadth of the territorial sea of each

State is measured. (50)

Similarly this principle, known as the equidistance principle, is further explained in Article 6(1):

[W]here the same continental shelf is adjacent to the

territories of two or more States whose coasts are

opposite each other.... In the absence of agreement,

and unless another boundary line is justified by special

circumstances, the boundary is the median line, every

point of which is equidistant from the nearest points of

the baselines from which the breadth of the territorial

sea of each State is measured. (51)

The Geneva Convention defined the continental shelf as:

[T]he seabed and subsoil of the submarine areas

adjacent to the coast but outside the area of the

territorial sea, to a depth of 200 metres or, beyond that

limit, to where the depth of the superjacent waters

admits of the exploitation of the natural resources of

the said areas. (52)

In the North Sea Continental Shelf Cases, the ICJ stated that the Truman Declaration's principle of delimitation by mutual agreement and delimitation in accordance with equitable principles had become the basis of the subject. The ICJ further decided that the ILC had not intended the equidistance principle to be a departure from the Truman Declaration: the "special circumstances" exception in Article 6 equated to the Truman Declaration's words effected on "equitable principles." (53) This led the Court to the conclusion that there was no obligatory rule of continental shelf delimitation. (54) The ICJ defined the continental shelf of the coastal state as a '"[n]atural prolongation of its land territory' existing 'ipso facto and ab initio, by virtue of its sovereignty over the land, and as an extension of it an exercise of sovereign rights for the purpose of exploring the seabed and exploiting its natural resources."' (55)

The rules regarding continental shelf delimitation were clarified in the 1982 United Nations Convention on the Law of the Sea (UNCLOS). (56) UNCLOS stated:

[A coastal state is entitled to a continental shelf

extending] throughout the natural prolongation of its

land territory to the outer edge of the continental

margin, or to a distance of 200 nautical miles from the

baselines from which the breadth of the territorial sea

is measured where the outer edge of the continental

margin does not extend up to that distance [subject to

delimitation with opposite and adjacent states with an

entitlement over the same area of the continental

shelf.] (57)

The outer limit of the continental shelf is subject to an overall maximum of 350 nautical miles or 100 nautical miles beyond the 2,500 meter isobath. (58) UNCLOS stressed that the coastal state is entitled to exercise sovereign rights "for the purpose of exploring [the shelf] and exploiting its natural resources." (59) These rights are exclusive and no other state may carry out such activities without the express consent of the coastal state. (60)

In the Malta-Libya Continental Shelf Case the ICJ recognized for the first time the continental shelf concept from UNCLOS as part of international customary law. (61) As a result, each coastal state, whether or not a signatory to UNCLOS, was entitled to a 200 nautical mile legal continental shelf, regardless of whether the shelf was continuous or extended that far. (62) For those states fortunate enough to have a continental shelf extending beyond 200 nautical miles, natural prolongation of their land territory remains the criteria, subject to Article 76, which determines the limits of their claims. (63)