The 1970s brought a confrontation between developing and developed countries in place of previous cooperation. The principle of permanent sovereignty over natural resources began to be used as a basis for legitimizing a more radical policy of nationalization and establishing associations of producers, such as the Organization of Petroleum Exporting Countries (OPEC)35 established in 1960 in Baghdad. At a special session of the UN General Assembly on the problems of raw materials and development, on 1 May 1974, Resolution No. 3201 was adopted entitled “Declaration on the Establishment of a New International Economic Order”.36 This resolution, strongly supported by developing countries,37 proclaimed, among others, full sovereignty of any state over its natural resources and all economic activity, including the right to nationalize funds or transfer its property to citizens, and granted the right to restitution and full compensation for exploitation and depletion of natural resources and all other resources of states and nations being under foreign occupation, foreign and colonial domination or apartheid, inter alia based on the principle of full sovereignty of any state over its natural resources and all kinds of economic activity, including the right to nationalize property or transfer ownership to citizens.38
In 1974, the UN General Assembly adopted the “Charter of States’ economic rights and obligations” covered by Resolution No. 3281 (XXIX)39 and supplemented by the “Declaration on New International Economic Order”. According to Article 2 (1) of this Declaration, every state is free to exercise permanent sovereignty, including possession, use, and disposal of all its wealth, natural resources, and economic activity. This document contains numerous provisions providing for the possibility of regulating foreign investments and their nationalization by the host state, granting the state, inter alia, the right to regulate and exercise authority over foreign investments within its national jurisdiction, in accordance with its laws and regulations, and in line with national objectives and priorities,40 and emphasizes the need for the host state to regulate and operate transnational corporations under its national jurisdiction and take measures to ensure that such activities are in accordance with its laws, rules, and regulations, as well as with their economic and social policy.41
During this period, in 1972 in Stockholm the first ever United Nations Conference on the protection of the human environment took place, during which the issue of the environment was addressed in a holistic way. The achievements of the conference included, in particular, the condemnation of nuclear weapons’ tests, the establishment of World Environment Day, and the adoption of an action plan on recommendations for further international action. The most important achievement of this conference was, however, the adoption of the Stockholm Declaration,42 which shifted the center of gravity of the discussion towards increasing international cooperation in the field of governance of natural resources. It contains a series of rules whose aim was to influence the behaviour of states in their environmental activities. The most important provision in this respect is provided in art. 21, which stipulates that states have a sovereign right to use their resources when applying their own environmental policy, and are responsible for ensuring that activities carried out within their jurisdiction or under their control do not harm other states or areas that are located beyond the limits of national jurisdiction. The Stockholm Declaration served as the basis for formulating guidelines for the United Nations Environment Programme (UNEP)43 of 1978 on the distribution of cross-border resources. These documents limited the exercise of sovereignty over natural resources by reference to the rules of international law, such as due diligence, good neighbourliness, and state liability for extraterritorial damage. The UN General Assembly then adopted in 1982, at the initiative of the International Union for Conservation of Nature,44 the World Charter for Nature,45 which formulated a number of environmental parameters regarding the use of natural resources, while taking into account the sovereignty of states over their natural resources.
The United Nations Convention on the Law of the Sea46 adopted in 1982 led to a thorough revision of the sovereignty of the coastal state over marine resources. This convention extended the width of the territorial sea to 12 nautical miles with full authority over natural resources. It also introduced new regulations regarding the breadth of the extended continental shelf and the exclusive rights of coastal states to the exploration of the continental shelf and the exploitation of its natural resources. This convention established a limit of 200 nautical miles for an exclusive economic zone.47 As in the case of the continental shelf, a coastal state does not enjoy full sovereignty within the exclusive economic zone, but only sovereign rights to natural resources, both animate and non-animate, from the seabed and subsoil, and covering waters. In addition to the rights, the UN Convention on the Law of the Sea also imposed obligations on the management of marine resources and natural resources.48 It requires all states to protect and preserve the marine environment, while recognizing their sovereign right to exploit their natural resources according to their environmental policy. It also establishes a detailed international cooperation system for the management of the seabed and its natural resources (in particular polymetallic concretes), which it considers to be the common heritage of mankind.
During this period, attention was also paid to the protection and rational use of natural resources.49 The necessity of reconciling economic development with environmental protection was covered by the concept of sustainable development, introduced into international policy by the World Commission on Environment and Development, known as the Brundtland Commission, in the 1987 report “Our common future”.50 The concept of sustainable development has been succinctly described as a development that meets the needs of the present generation without diminishing the prospects of future generations to meet their own needs. In this respect, the UN General Assembly convened in 1989 a conference on Environment and Development. The conference was held in 1992 in Rio de Janeiro, and, due to the thematic reach and interest of states, it was called the “Summit of the Earth”. It continued the achievements of the Stockholm conference. The main results of the Rio conference were: the “Agenda 21” document,51 the Framework Convention on Climate Change,52 the Convention on Biological Diversity,53 the Statement of Principles for a Global Consensus on the Management, Conservation, and Sustainable Development of all Types of Forests,54 and the Rio de Janeiro Declaration on Environment and Development.