3.3.1. Hard law

Even leaving soft law aside for now, the breadth of sources of law that traditional hard law encompasses is in itself considerable. Article 38 of the Statute of the International Court of Justice is often used as a codification of the sources of international law. It provides:

  1. The Court, whose function is to decide in accordance with international law such disputes as are submitted to it, shall apply:

    1. international conventions, whether general or particular, establishing rules expressly recognised by the contracting States;

    2. international custom, as evidence of a general practice accepted as law;

    3. the general principles of law recognised by civilised nations;

    4. subject to the provisions of Article 59, judicial decisions and the teachings of the most highly qualified publicists of the various nations, as subsidiary means for the determination of rules of law.

    This provision shall not prejudice the power of the Court to decide a case ex aequo et bono,[1] if the parties agree thereto.

  2. These sources will be examined in turn, save for judicial decisions and juristic writings as these are merely subsidiary means for the determination of the content of international law. International conventions

International conventions range from bilateral agreements, such as extradition treaties and the Australia–United States Fair Trade Agreement, through to multilateral agreements such as the Geneva Conventions to which almost all countries of the world are signatories. A treaty or convention only has the status of international law for those states that have signed and ratified it. How this is accomplished, and the effect its ratification may have in local law, is a domestic matter that varies from one jurisdiction to another.

In Australia, treaties and conventions may be ratified by the Federal Cabinet, without the need for the passage of legislation or to be debated in Parliament. However since 1996, a policy has been adopted requiring a treaty to be tabled in both houses of Parliament for 15 sitting days, for a Parliamentary Joint Standing Committee on Treaties to engage in public consultation concerning the proposed ratification of the treaty, and a National Interest Analysis in respect of the treaty to be prepared, before it is ratified.[2]

In order to comply with its obligations under the instrument in question, it will then usually be necessary for the government to introduce legislation into Parliament which will be debated in the usual manner. This is also necessary in order for the instrument to have any effect in Australian law, other than as a general guide for the exercise of executive discretion and statutory interpretation.[3] This differs from the position in certain other jurisdictions, such as the United States, although there the President requires the concurrence of two-thirds of the Senate before entering into a treaty.[4] International custom

Customary international law is found where there is both a “common, consistent and concordant”[5] pattern of behaviour amongst states, without substantial dissent from other states,[6] coupled with the acknowledgment that the practice is observed because it is as a legal obligation; or in law Latin, that opinio juris sive necessitatis or simply opinio juris is present.[7] Opinio juris (and indeed some evidence of state practice) can in appropriate cases be determined from the declarations that a state makes in international fora,[8] from its domestic legislative, executive and judicial institutions, and even from the existence of a treaty on the topic that other states have ratified but that it has not.[9]

Therefore in simple terms, it could be said that customary international law is law because it is regarded as such by international actors.[10] More so than domestic law, it is thus a social construction, since its very existence depends on the subjective beliefs of the actors who comply with it. In that respect, the process for formation of customary international law does not seem so very different from the New Haven approach referred to at Section 3.1.1, according to which international law is found wherever there is a confluence of authority (that is, where a decision is perceived to be made legitimately by those whom it purports to cover) and control (that is, the decision does in fact influence their behaviour). In New Haven terms, control equates to state practice and authority to something like opinio juris.[11]

Much of what begins as customary law ends up being codified by treaty, as for example in the case of the rules of war that are now found in the Geneva Conventions. However, new customary international law is in the process of formation all the time, and there are circumstances in which this can take place extremely quickly.[12]

To give a recent example of this, following the 11 September 2001 terrorist attacks on New York City and Washington DC, United States President George W Bush declared that in bringing those responsible to justice, “we will make no distinction between the terrorists who committed these acts and those who harbor them.” Subsequently dubbed the “Bush Doctrine,” this principle has since been affirmed by resolutions of the United Nations General Assembly and Security Council and begun to be acted upon by states. On one account, it thereby became a new principle of “instant” customary international law.[13]

On this basis, it is certainly possible for norms of Internet governance to become customary international law in the orthodox sense quite quickly. In such cases, sufficient evidence of state practice and opinio juris may simply take the form of each affected state communicating their recognition of the practice as customary law, or by means of a resolution of a body such as the General Assembly of the United Nations.[14]

Whilst there is doubt as to whether the new law merchant can be said to have made this transition (it is, after all, largely created and observed by non-state actors),[15] the early and full involvement of states in the IGF (and through the GAC in ICANN) may make many of the norms of Internet governance more promising candidates for promotion to the status of international law.[16] This question will be reconsidered in the conclusion to this chapter. General principles of law

Little need be said about the general principles of law that form another source of hard international law, save that they are thought to include the principles of equity and estoppel, which are broadly comparable to those concepts as known in common law jurisdictions, and provide a moderating influence on the strict application of the law in cases where it is necessary to avoid unfairness.[17]

Some would also include within this category the jus cogens—literally, compelling law—which Article 53 of the Vienna Convention defines as “a peremptory norm of general international law ... accepted and recognised by the international community of states as a whole as a norm from which no derogation is permitted and which can be modified only by a subsequent norm of general international law having the same character.”[18] Examples include the prohibitions upon torture, slavery, piracy and genocide.



“In justice and fairness.”


Commonwealth of Australia, Review of the Treaty Making Process (1999)


Minister for Immigration and Ethnic Affairs v Teoh (1995) 183 CLR 273


Constitution of the United States of America, 17 Sep 1787, Article VI and Article II, section 2


Fisheries Jurisdiction Case (United Kingdom v Iceland) (Merits) [1974] ICJ Reports 3, 50


Case Concerning Military and Paramilitary Activities in and against Nicaragua (Nicaragua v United States of America) (Merits) [1986] ICJ Reports 14, 98


Polyukhovich v The Commonwealth (1991) 172 CLR 501, 559–560


Langille, Benjamin, It’s “Instant Custom": How the Bush Doctrine Became Law After the Terrorist Attacks of September 11, 2001 (2001), 151–152


North Sea Continental Shelf Cases (Federal Republic of Germany v Denmark; Federal Republic of Germany v Netherlands) [1969] ICJ Reports 3, 41


Arend, Anthony C, Legal Rules and International Society (1999), 33.


Where New Haven scholars diverge from orthodoxy is of course in contending that non-state actors can be involved in this process.


North Sea Continental Shelf Cases, 230 per Lachs J


Langille, Benjamin, It’s “Instant Custom": How the Bush Doctrine Became Law After the Terrorist Attacks of September 11, 2001 (2001)


Van Bogaert, E R C, Aspects of Space Law (1986), 20


Zamora, Stephen, Is There Customary International Economic Law? (1989); Chinkin, C M, The Challenge of Soft Law: Development and Change in International Law (1989) , 857


Biegel, Stuart, Beyond Our Control?: Confronting the Limits of Our Legal System in the Age of Cyberspace (2001), 172


White, Margaret, Equity—A General Principle of Law Recognised by Civilised Nations? (2004)


Vienna Convention on the Law of Treaties, 23 May 1969, 1974 ATS No 2 (entry into force 27 Jan 1980)