Municipal courts and municipal law deal chiefly with domestic issues. But Judges and practitioners, accustomed to the application of local laws to local issues, find that the pattern of litigation is changing. As our countries move into a world of transnational trade and commerce and agreed international standards touching social, environmental and economic issues, international law has an increasing influence on the content of municipal law. In earlier times, when international law related chiefly to the affairs of sovereign States, it had comparatively little effect on municipal law. The ordinary laws governing relationships between individuals, the powers of government and prohibited conduct were not the concern of the international community.

With increasing frequency, especially in the last twenty years, the international community has sought to contain international tensions and consolidate peaceful relations by treaties setting common standards to be implemented by nation States according to their own legal systems. Municipal courts have been called on to implement a changing international legal order. Municipal courts, more than international tribunals, have become the expositors of international law.

When international law speaks to matters within the domain of municipal law, the question whether and to what extent municipal law responds must be answered by national courts and legal professions. Some legal systems, embracing the monist theory, treat international law and municipal law as parts of a single body of law, administered in accordance with an internal set of rules. Kelsen perceived international law to be the basis of the national legal order in the sense that an international legal norm defines the organs of a legitimate national government and thereby delegates the authority to create a national legal order. Other legal systems, Singapore and Australia among them, regard international law and municipal law as distinct. This is the theory of dualism. It distinguishes between the two systems on these: first, the subjects of municipal law are individuals while the subjects of international law are nation States. Secondly, the juridical origins of the two systems are different. The common law jurisdictions find municipal law in statutes and regulations and in judicial decisions. The sources of international law are the customary law of nations, treaties, binding resolutions of the United Nations Security Council and the general principles of law recognised by the courts of civilised countries.

Whether a State embraces the monist or the dualist theory, the practical question that has to be addressed by a municipal court is whether and to what extent the provisions of international law are to be applied to the case in hand. That is not to say that municipal courts apply international law: they do not. In the judicatures of common law countries, only municipal law is applied. But the incorporation or transformation of international law into municipal law is often the means by which a State discharges its international legal obligations.

The international community has a legitimate interest in two aspects of the work of municipal courts. The first aspect relates to the implementation of the provisions of international law by the municipal legal system. That depends on the principles of municipal law that govern the adoption of international law. The second aspect relates to the revelation by court decisions of the way in which the rule of law operates in a particular society. I turn first to the principles governing the domestic application of international law.

Australian practice, I must say, in this respect substantially follows English precedent. The citation of English and Australian authority by the CJ in the recent judgment of the Court of Appeal of Singapore in Public Prosecutor v Taw Cheng Kong leads me to proceed on the footing that no difference will be found in this respect between the law and practice of Singapore and Anglo-Australian law and practice.

1. The common law and customary international law

Municipal law distinguishes between customary international law, embodying the practice of civilised nations as acknowledged by jurists, and international law derived from treaties. Blackstone’s opinion was that the law of nations - that is, the whole of customary international law - is part of the law of the land. That principle of incorporation was adopted in the 18th century and was affirmed at the beginning of this century by Lord Alverstone CJ in 1905 who insisted on proof that the proposed norm of customary international law had already been recognised and acted upon in England or was of such a nature that no civilised state would repudiate it. Then Lord Atkin, delivering the opinion of the Privy Council in Chung Chi Cheung v The King, said:

"It must be always remembered that, so far, at any rate, as the Courts of this country are concerned, international law has no validity save in so far as its principles are accepted and adopted by our own municipal law. The Courts acknowledge the existence of a body of rules which nations accept amongst themselves. On any judicial issue they seek to ascertain what the relevant rule is, and, having found it, they will treat it as incorporated into the municipal law, so far as it is not inconsistent with rules enacted by statutes or finally declared by their tribunals."

This doctrine of incorporation was affirmed in later cases. In the Tin Council case in the House of Lords, Lord Oliver pointed out that incorporation is limited to the existing rules of international law and municipal courts have no authority "to legislate a rule into existence for the purposes of domestic law and on the basis of material that is wholly indeterminate."

Now arguably, the Australian approach to customary international law is different. In Chow Hung Ching v The King Dixon J adopted the opinion of Prof. Brierly that international law "is not a part but one of the sources of English law". This proposition transforms rather than incorporates the international norm into the common law and would accept the authority of the court to develop the transformed international norm to meet the exigencies of each case. Whichever approach is adopted, the court must first determine whether the international norm contended for has been acted upon, or would certainly be acted upon, by the community of nations. Then it must appear that there is no statute or binding court decision inconsistent with the proposed norm.

2. Treaties and the statutes implementing them

Under the Westminster form of government, the Crown or the Executive Government has the exclusive power to enter into treaties and thereby bind the State. But the Executive Government is not the repository of legislative power and it cannot enact new law by the exercise of executive power; new laws must be enacted by the legislature or with the legislature’s authority. Therefore, it has been held in Australia as in England:

"that the provisions of an international treaty to which Australia is a party do not form part of Australian law unless those provisions have been validly incorporated into our municipal law by statute."

When the provisions of a treaty are enacted in the terms in which the treaty is drawn, however, the municipal court construes these terms not by reference to the municipal rules of statutory construction but by the international rules applied in the interpretation of treaties. When The Hague Rules were incorporated into the Carriage of Goods by Sea Act 1924 (UK), Lord MacMillan said:

"It is important to remember that the Act of 1924 was the outcome of an International Conference and that the rules in the Schedule have an international currency. As these rules must come under the consideration of foreign Courts it is desirable in the interests of uniformity that the interpretation should not be rigidly controlled by domestic precedents of antecedent date, but rather that the language of the rules should be construed on broad principles of general acceptation."

Now a similar issue arose in Australia when the Racial Discrimination Act 1975 (Cth) was enacted in substantially the same terms as, and to give effect to, the International Convention on the Elimination of All Forms of Racial Discrimination. In Koowarta v Bjelke-Petersen, I observed that:

"[w]hen Parliament chooses to implement a treaty by a statute which uses the same terms as the treaty, it is reasonable to assume that Parliament intended to import into municipal law a provision having the same effect as the corresponding provision of the treaty."

The reasons for this approach are "certainty and uniformity of application". Therefore, the basic rule of interpretation is to be found in Art 31 of the Vienna Convention, the work of the UN International Law Commission.

However, the interpretation of some treaty provisions may be affected by the prior history of the rule. If the treaty simply expresses a rule, especially a rule of commercial or maritime law, which has been applied by municipal courts before the treaty was entered into, the true meaning of the treaty rule may be found in judicial precedent. This has been the subject of discussion in Australia.

3.  The effect of treaties on the construction of statutes generally

The proposition that the provisions of treaties are not part of municipal law unless incorporated by statute means that, under municipal law, statute prevails over treaty where there is any inconsistency between the two. Speaking for the Court of Appeal in Seow Teck Ming v Tan Ah Yeo, Chan Sek Keong J said:

"[I]t is settled law that the duty of the court is to give effect to national law and not international law if there were a real conflict between them."

The priority accorded to municipal law can, of course, be ceded by statute so that the provisions of a treaty override an inconsistent municipal law. When Singapore statutorily incorporated the United Nations Convention on Contracts for the International Sale of Goods 1980, the Act provided that the Convention should prevail over other laws to the extent of any inconsistency.

Although treaties do not become part of municipal law unless incorporated by a valid statute, it is erroneous to think that unincorporated treaty provisions are wholly irrelevant. Such provisions have been held to be relevant to the construction of statutes where the language of a statute is either so general or ambiguous that it can be interpreted to conform with treaty obligations. Australian courts, following English authority, construe ambiguous statutes to accord with treaty obligations "at least in those cases in which the legislation is enacted after, or in contemplation of, entry into, or ratification of, the relevant international instrument." The explanation of this approach to the construction of an ambiguous statute is the presumption that "Parliament, prima facie, intends to give effect to Australia's obligations under international law." But as Lord Denning reminds us, where a treaty is expressed in terms that are:

"so wide as to be incapable of practical application, … it is much better for us to stick to our own statutes and principles, and only look to the Convention for guidance in case of doubt."

4. The effect of international law on the common law

International law generally has now been recognised in Australia as a legitimate source of development of the common law. This approach is similar to the view taken by Dixon J that customary international law is a source of the common law. With the concurrence of two other Justices in Mabo v Queensland [No 2], I said:

"The common law does not necessarily conform with international law, but international law is a legitimate and important influence on the development of the common law, especially when international law declares the existence of universal human rights."

In Minister for Immigration and Ethnic Affairs v Teoh, Mason CJ and Deane J, cautioned against too ready an incorporation of international law norms into municipal law. Their Honours said:

"The provisions of an international convention to which Australia is a party, especially one which declares universal fundamental rights, may be used by the courts as a legitimate guide in developing the common law. But the courts should act in this fashion with due circumspection when the Parliament itself has not seen fit to incorporate the provisions of a convention into our municipal law. Judicial development of the common law must not be seen as a backdoor means of importing an unincorporated convention into Australian law."

The adoption by Australia of the First Optional Protocol to the International Covenant on Civil and Political Rights conferred on individuals a direct right of access to the Human Rights Committee sitting in Geneva. It is impossible to suppose that the jurisprudence that the Committee will develop in construing the International Covenant will not be regarded by Australian courts if similar issues arise for determination by those courts. Sir Robin Cooke, as he then was President of the New Zealand Court of Appeal in 1994, expects that New Zealand courts will give effect to the International Covenant. But in England, the common law has reacted more conservatively to the existence of an unincorporated treaty, in that instance the European Convention on Human Rights. Australian sensitivity to a determination of the Human Rights Committee resulted in federal legislation designed to nullify the effect of a State law which the Committee held to be inconsistent with the Covenant.

5. Treaties and discretionary powers

It would be no great leap of principle to presume that, when Parliament creates a discretionary power, it intends the repository of the power either to exercise the power consistently with treaty obligations or at least to have regard to treaty obligations in exercising the power. That question arose in Teoh’s case, a case which stimulated some controversy. The Minister ordered a foreign national, convicted of a drug offence, to be deported. The deportee was married to an Australian with young Australian children. The United Nations Convention on the Rights of the Child, to which Australia is a party, directs that the best interests of the child should be a primary consideration in all actions concerning children. That direction had not been taken into account in ordering the deportation. A majority of the High Court held that, although the Convention was not a source of individual rights and obligations, there was nothing in the statute to exclude consideration of the Convention by the Minister. Mason CJ and Deane J said:

"Rather, ratification of a convention is a positive statement by the executive government of this country to the world and to the Australian people that the executive government and its agencies will act in accordance with the Convention. That positive statement is an adequate foundation for a legitimate expectation, absent statutory or executive indications to the contrary, that administrative decision-makers will act in conformity with the Convention and treat the best interests of the children as 'a primary consideration'."

The Court quashed the decision to deport, holding that if the Minister did not intend to give effect to the Convention direction, he was bound to give the deportee an opportunity to submit that the Convention direction ought to be followed. The Minister, somewhat concerned by the implications of the Teoh decision, subsequently observed that the ratification of a treaty "is a statement to the international community to observe the treaty measures in question; it is not a statement to the national community - that is the job of the Legislature, not the Executive." Although legislation has been proposed to override the principle of the Teoh decision, no legislation has yet been enacted.

In a similar case in New Zealand, the Minister argued that he was entitled to ignore the International Covenant on Civil and Political Rights and the Convention on the Rights of the Child in ordering a deportation. Sir Robin Cooke said:

"That is an unattractive argument, apparently implying that New Zealand's adherence to the international instruments has been at least partly window-dressing."

However, a final decision on the argument was not given in that case.

In England, an issue of principle similar to that in Teoh's case arose before the House of Lords in Ex parte Brind. It was argued that, as the courts presume that Parliament intends to legislate in conformity with treaty obligations, it should be presumed that discretionary powers are to be exercised within limits imposed by treaties. The argument was rejected. Lord Bridge thought that proposition went beyond a mere rule of statutory construction to resolve an ambiguity and would impute to Parliament an intention to enforce conformity with the treaty. Clearly, the thesis that the Executive should not blow hot and cold in its international dealings and in exercise of its domestic discretions will be subject to further judicial examination.

The implication of the Teoh decision is far reaching. If the existence of a ratified but unincorporated treaty gives rise to a "legitimate expectation" that its terms will be observed and if a general discretionary power is exercised without observing those terms, the decision is voidable unless the party affected thereby has been given an opportunity to submit that the treaty should be observed. Teoh might prove to be a growth point of principle governing the effect of international law on executive power.

Of course, municipal courts will often refer to decisions of international courts and tribunals where such decisions have construed a treaty or defined a proposition of international law. But the modern plethora of treaties and the domestic subject matter of many of them will continue to require expositions of treaties by municipal courts. Australia, for example, is party to more than 900 international instruments. It may not be appreciated that the experience of municipal courts in dealing with domestic issues gives them a special competence to evaluate the operation of treaties or proposed treaties affecting domestic issues. That experience could provide a useful reference point for an Executive Government invited to conclude a treaty impinging on the commerce or conduct of its people.

I have not canvassed the problems raised by the extraterritorial operation of national laws and the doctrines which restrict the justiciability of claims based on the penal, revenue or other "public laws" of a foreign State. I have simply footnoted some cases relating to this point. Though these topics are important to international relations, they stand outside a discussion of the effect of international laws. Treaties of the future may standardise and codify the relevant rules and thereby reduce the possibility of international tensions arising from the decisions of municipal courts on issues arising from the laws and sovereign acts of other States.

Apart from the international community's interest in the exposition of international law by municipal courts, the exercise by those courts of their ordinary jurisdiction plays an important, though largely unacknowledged, role in international relations.

However, as we noted earlier, international relations in the modern age are legitimately concerned with many aspects of the municipal legal order. They are concerned with the operation of the laws of trade and commerce, of shipping and the movement of currencies, of criminal law (especially the laws dealing with terrorism, drug trafficking and organised crime), of the laws affecting human rights, official corruption, the environment, intellectual property, resources and energy, health and quarantine. Irrespective of a nation State's adoption of international standards by its municipal law, the way in which municipal courts exercise their respective jurisdictions in dealing with these subjects is material to the relationship of one nation State with another.

The independence of the courts, the decisions they give, the sentences they impose, the procedures they adopt, the efficiency with which they dispose of their business are the product of, and a formative influence upon, the society in which they exercise their jurisdiction.

The decisions of municipal courts reveal the extent to which a society is governed by the rule of law, the competence and independence of the judiciary, the efficiency of judicial remedies and the restraints on discretionary power. A true appreciation of the dynamics of a society cannot be had unless the actual working of its municipal courts is understood. The bare text of constitutions or laws must be clothed with the decisions of the courts before the true shape of the legal system can be seen.

The nation States of Asia and the Pacific contain a variety of cultures, laws and systems of government. Each of those legal systems has evolved to meet the challenges of the particular society and finds its legitimacy in local conditions. But the diversity of cultures, laws and systems of government is pregnant with the possibility of international misunderstanding. When international misunderstandings have arisen with respect to the exercise of jurisdiction by municipal courts, the cause has often times been an insufficient appreciation of differences in culture, in laws, in systems of government or in the relationship that exists between the judicial and the political branches of government.

In this, the fiftieth Anniversary of the signing of the Universal Declaration of Human Rights, an example may be found in the definition and protection of human rights. In 1995, at and subsequent to a meeting of the Chief Justices of nations of Asia and the Pacific, the Beijing Statement was adopted, setting out the objectives and functions of our respective judiciaries to be as follows:

"(a)  to ensure that all persons are able to live securely under the Rule of Law;

(b)  to promote, within the proper limits of the judicial function, the observance and the attainment of human rights; and

(c)  to administer the law impartially among persons and between persons and the State."

It is one thing to assert a judicial function to promote the observance and attainment of human rights; it is another thing to agree on their practical content and the "proper limits of the judicial function". The culture and system of government of each nation State affects that State's concept of human rights and the part they play in the municipal legal order. Diplomatic tensions on issues of human rights could be moderated by a better understanding of the municipal legal order.

It is anomalous, I suggest, to confine diplomacy to exchanges between the Executive branches of governments if the point of the exchanges is the practical working of the municipal legal system. Judicial exchanges, explaining the legal, cultural and social factors that contribute to municipal decisions, can dispel misunderstandings that might otherwise go unexplained. And such exchanges would assist in providing practical answers to problems that arise in the course of international dealings.

The trader may want to know if judicial relief is available when excessive customs duty is levied or administrative powers are misused. The investor may need to discover the judicial remedies available to protect an investment or to enforce a security. The inventor, local or foreign, will be interested to find out if there is effective protection of intellectual property. Environmentalists and other nation States wish to discover whether there are legal remedies to enforce compliance with environmental standards or obligations prescribed by treaty. Families are anxious to ensure that there is legal protection for expatriate workers. A custodial parent seeks assurance that wrongfully abducted children will be returned. Law enforcement agencies want to be confident that no country should be a haven for drug dealers, organised crime figures or terrorists.

The factors which are relevant to the assessment of a State's commitment to the rule of law are not ascertained merely by reference to the laws of a State. The predictability and normative effect of the law depends on the actual practices and traditions of each nation State. It is surprising, perhaps, that so little attention has been given internationally to the significance of the work of municipal courts. A better assessment of their work would do much to dispel international misunderstandings and to focus attention more precisely on some of the sticking points of international diplomacy. A real understanding of the way in which the rule of law operates in each State and of the way in which the law of the State works to protect legal interests that are the concern of other States can be built gradually by free discussions between the Judges of the respective States. Such discussions are an untapped source of international understanding and a valuable means of diminishing tensions that arise from a failure to appreciate accurately the institutional differences that reflect the differing cultures and systems of government in our region. Judicial resources could be harnessed to enhance regional understanding. But how is this to be achieved?

Not by brief and fortuitous meetings among lawyers attending a conference, valuable though such contacts may be. Rather, the experience, intellect and authority of the senior judiciary of the Region should be drawn upon in a Forum in which they would focus, each from his or her national standpoint, on the great issues of international concern falling within their respective jurisdictions. In such a Forum, mutual confidence and understanding of different viewpoints could be built and, if there be substantial issues in controversy, they could be defined more precisely and addressed with a real prospect of resolution. It is surely in the interests of the Region to create a framework in which differences can be explained and the legal infrastructures necessary for peaceful co-existence and international trade, commerce and intercourse can be improved.

An Asian-Pacific Judicial Forum of this kind, constituted chiefly by senior judiciary, would require the support and encouragement of the Executive Governments of participating nation States. The judiciary must meet with the clear understanding that their exchanges will be seen to be beneficial to their own States and to the Region. The Forum would have a serious diplomatic purpose: the development in time of a clearing house of ideas that are relevant to international relations. It would become a valuable adjunct to the diplomatic and political exchanges that are already an established feature of Regional activity.

No nation State should seek to exercise a controlling influence on the organisation of the Forum. Its secretariat, small and relatively inexpensive, should be funded by the participating States. Desirably, the headquarters should be in one of the ASEAN capitals. The membership should consist of the ASEAN nations, their regional dialogue partners and those Pacific nations who would wish to join - probably the larger Pacific nations whose breadth of international legal interests would approximate those of the smaller ASEAN nations. The People's Republic of China, Japan and the Republic of Korea would be valuable contributors to the Forum.

Its future development and its agenda must be left until its membership is established. Many lessons would be learnt in the exchanges. For example, the highly developed system of judicial training in Japan would no doubt be of interest to many regional judiciaries. Similarly, the judicial orientation courses for newly appointed judges in Australia may provide a model for other common law countries. The technological experiences of the Singapore Courts, of which the Integrated Criminal Justice System is a notable example, would offer a valuable resource for court organisation and case management. And the meetings themselves would create a climate of mutual judicial support that would strengthen the legal infrastructure of the Region.

Initially, seminars of a few senior judges either from each participating nation or from each nation in a sub-regional cluster would be convened with agenda devised by the secretariat. Investment and taxation regimes, the definition and protection of human rights, environmental protection and international criminal law are topics that would command early attention. The discussions would be led by invited authors of papers, whether judges or academic lawyers, drawn from different jurisdictions. The Forum would grow according to its utility in enhancing mutual respect and understanding, in providing mutual assistance and in developing a sense of regional identity of interest.

This proposal should not duplicate any existing arrangements. In particular, although the Chief Justices of the participating States would be invited to approve the existence of the Forum, to support attendance by their judges and to constitute a Board to supervise the secretariat, there would be no duplication of the biennial meetings of Chief Justices held in conjunction with the meetings of Lawasia. Those meetings not only include many more Chief Justices than could be accommodated in a working Forum; the purpose of their meeting is largely to address common organisational problems rather than to discuss the way in which the decisions of their courts are reached and the laws that are applied.

It has been for me a great satisfaction to learn that the Australian Government, conscious of the need to ensure that the future of the Forum should be in the hands of participating nations, has authorised the provision of an interim secretariat if the notion of a Regional Judicial Forum should prove acceptable to other nations. The Centre for Democratic Institutions of the Australian National University in Canberra, a Centre funded by the Australian Government, would undertake the organisation of an opening seminar.

Therefore, Chief Justice, I venture to suggest that the time has passed when the work of municipal judiciaries is immaterial to international relations and when the voices of municipal judiciaries are silent on issues which concern other nations. An Asian-Pacific Judicial Forum would provide a framework for strengthening the rule of law and thereby contributing to the peace, the order and the good government of our Region.