3. Conceptual developments and the new basic principle of international law

The work of the International Law Commission, learned societies, and distinguished writers of international law have greatly clarified the conceptual framework governing this particular area of the law. First, a useful distinction has emerged that separates international "responsibility" from international "liability," the former arises from unlawful acts while the latter has come to encompass both lawful and unlawful activities. The idea of state liability for acts not prohibited by international law has also emerged in this context.⁴

This distinction has not passed unchallenged. Brownlie has made the argument that the normal principles of state responsibility can well sustain liability, particularly as it concerns extra-hazardous operations.⁵ In this context the critical issue is the content of the rules and not the distinction between lawful and unlawful activities, especially since either way leads to reparation and compensation. In practice, however, this distinction is gaining ground in several treaty regimes, although it is also true that a number of legal consequences are attached to given activities resulting in damage irrespective of their lawful or unlawful character.

A second conceptual development serves as a useful analytical tool: the distinction between "primary" and "secondary" rules. The former relate to obligations, the breach of which may lead to responsibility, while the latter relate to the legal consequences of failure to comply with the obligations arising from the primary rules. Secondary rules are those specifically dealing with the issue of responsibility and liability, although these issues cannot always actually be separated from the operation of the primary rules.

The important document prepared by the Italian government on the international law of the environment⁶ indicates that in practice one can observe significant developments in the treaty rules dealing with the environment (the primary rules), but not a parallel evolution in the rules on responsibility, which are either non-existent or overly general in those regimes. The result is that the secondary rules lag behind those developed in the primary level.

In spite of these shortcomings, practice shows the acceptance of a general principle of responsibility for environmental damage caused by activities within state jurisdiction or control.⁷ While this principle is generally accepted, it would not seem that the International Law Commission approach of regarding its violation as an international crime meets with general approval. The existence of a principle of international law embodying the obligation not to degrade the environment is further reinforced by the new conceptual approaches influencing the development of the law in this field, namely the concepts of intergenerational equity, human rights, and environmental security.