XYZ v The Commonwealth

[2006] HCA 25

---

(Judgment by: Kirby J)

XYZ
v The Commonwealth

Court:

Judges: Gleeson CJ
Gummow
Hayne
Crennan JJ

KirbyCallinan
Heydon

Judgment date: 17 November 2005

---

Judgment by:
Kirby J

[54] These proceedings on a case stated for the opinion of the Full Court ^[82] concern the constitutional validity of two sections ^[83] of the Crimes Act 1914 (Cth) ("the Crimes Act"). It is pursuant to those sections that the plaintiff, who is an Australian citizen, has been charged with sexual offences involving "a person who is under 16" ^[84] . The offences are alleged to have occurred in the Kingdom of Thailand.

[55] On 17 November 2005, having heard the arguments of the parties, this Court answered the questions stated in terms upholding the validity of the sections. I agreed in the answers given by the Court. It remains for me to state my reasons.

[56] In his text on constitutional law, Professor P H Lane states that "external affairs" was "once a phrase that had some kind of peculiar connotation with a resulting extent". He complains that now this Court "does not explain 'external affairs' as an identifiable notion" ^[85] . Whilst this statement is not entirely accurate, at least in respect of that aspect of "external affairs" upon which the Commonwealth primarily relied for the validity of the legislation contested in this case, the general complaint deserves attention. The issue is of constitutional importance because of the risk, expressed by the plaintiff, that the approach to the constitutional validity of the federal legislation urged by the Commonwealth could cause an unravelling of the balances established in the applicable federal legislative power by reference, in particular, to facts, persons or things existing beyond Australia's geographical borders.

[57] Unquestionably, this is a significant issue for the Constitution and for the meaning and limits of the powers of the Federal Parliament. The plaintiff charged that, in the recent elaborations of the "external affairs" power ^[86] , this Court had taken a wrong turning. He submitted that the Court should now return to earlier doctrine lest the more recent explanation of the power become entrenched so as to wound the federation ^[87] .

[58] This case affords an occasion suitable to consider this submission ^[88] . In the end, it does not avail the plaintiff, for the constitutional validity of the legislation may be upheld on an alternative elaboration of the power. However, the point needs to be noticed so that it is not lost for a future occasion when it might prove to be determinative.

The facts and legislation

[59] The facts: The plaintiff is charged with offences against ss 50BA and 50BC of the Crimes Act. He denies his guilt of the alleged offences. However, no submission was put to the effect that, if the offences are constitutionally valid, they do not apply to him, to a "person who is under 16" and to the place outside Australia (namely Thailand) where the "physical elements ... of the offence[s]" ^[89] are alleged to have occurred.

[60] The details of the charges are set out in the reasons of Gummow, Hayne and Crennan JJ ^[90] . It is not necessary for me to repeat them. One point to notice at the outset is that, as the general age of consent in Thailand was said to be fifteen years, there is thus a possibility that, under the impugned provisions, an Australian citizen or permanent resident might be rendered liable in Australia for acts happening in Thailand that would not constitute a criminal offence in that country. The plaintiff complained about this and about other features of the legislation. It will be necessary to return to those complaints ^[91] . Whether they ultimately have any relevance to the accusations against the plaintiff is unknown, lying as they do outside the facts appearing in the case stated.

[61] International background: The federal legislation challenged in these proceedings has a background. It can best be understood in the context of a number of events occurring both within and outside Australia.

[62] Of critical importance was the adoption by the General Assembly of the United Nations, on 20 November 1989, of the Convention on the Rights of the Child ("the CRC"). Australia ratified that Convention in January 1991 ^[92] . So have most other nation states. Stimulated by the CRC, and by the commitments contained within it ^[93] , a number of initiatives were taken within the United Nations Organisation, designed to protect children from various harms and dangers ^[94] . Eventually, an Optional Protocol to the CRC was adopted by the General Assembly on 25 May 2000. By Art 4.2(a) of that Protocol it is provided that:

Each State Party may take such measures as may be necessary to establish its jurisdiction over the offences referred to in article 3, paragraph 1 [including '[s]exual exploitation of the child'] ... (a) [w]hen the alleged offender is a national of that State or a person who has his habitual residence in its territory.

[63] Australia, through the federal Executive Government, took a leading part in drafting, proposing and securing the adoption of this Protocol ^[95] . However, the Commonwealth did not rely upon the Protocol as a treaty which the provisions of the Crimes Act in question were designed to implement ^[96] . Nevertheless, the Commonwealth submitted that the Protocol indicated that the subject matter of the Crimes Act was one of "international concern" and was relevant to Australia's relationships with other nation states and with relevant international organisations.

[64] The plaintiff raised no objection to the tender by the Commonwealth of a great deal of material concerning initiatives within the international community, and in Australia ^[97] , concerning the protection of children from sexual acts by foreign nationals ^[98] . Such material provides further background against which the impugned provisions of the Crimes Act may be understood.

The issues

[65] As I approach these proceedings, there are five issues:

(1)

The geographical externality issue: Is a federal law that operates extraterritorially with respect to facts, persons or things geographically external to Australia, for that reason alone, necessarily a law with respect to "external affairs" within the meaning of s 51(xxix) of the Constitution? Does the present authority of this Court uphold that proposition? If so, should this Court simply apply that authority and, without more, answer the question stated adversely to the plaintiff, notwithstanding the criticisms of that authority advanced by the plaintiff?

(2)

The leave to reopen issue: Contingently on a determination of the first issue adverse to his arguments, the plaintiff sought leave, if necessary, to reopen such authority of the Court as upheld the geographical externality principle for the content of the "external affairs" power in the Constitution. Is leave necessary to permit any such reopening of a past ruling concerning the meaning of a provision of the Constitution? If so, should such leave be granted?

(3)

The reversal of authority issue: If leave to reargue the correctness of the geographical externality principle for the meaning of s 51(xxix) of the Constitution is granted or is not required, should the principle be reconsidered by the Court in the light of earlier authority, the language, structure and purpose of s 51(xxix) and other relevant considerations? Should that principle be overruled or re-expressed having regard to the plaintiff's arguments?

(4)

The alternative validity issue: If the geographical externality principle should be overruled or re-expressed, or if that question should be reserved for a decision in a case where it is essential to the result, is the law impugned by the plaintiff in these proceedings nonetheless valid under the Constitution because:

(a)

it is adequately demonstrated that the law in issue is with respect to a matter of "international concern" affecting Australia and thus, without more, concerns a subject within s 51(xxix) of the Constitution; or

(b)

it is sufficiently connected with the legislative powers of the Federal Parliament with respect to crimes of the nominated type committed overseas by an Australian national or permanent resident on the basis that such crimes affect, or may affect, the external relations of Australia with other nation states or international organisations?

(5)

The proportionality issue: Assuming that one of the suggested criteria for establishing the validity of the law impugned by the plaintiff is arguable, is the law nonetheless invalid because, upon analysis, it is disproportionate (not "reasonably appropriate and adapted") to the power of the Federal Parliament to enact such a law in the terms of the contested provisions of the Crimes Act?

The geographical externality principle

[66] The geographical externality criteria: The reasons of Gummow, Hayne and Crennan JJ explain the geographical externality principle, as it has been elaborated to describe the ambit of the powers of the Federal Parliament to make laws with respect to "external affairs", pursuant to s 51(xxix) of the Constitution ^[99] .

[67] Those reasons state that the principle, in the terms in which it was expressed in Victoria v The Commonwealth (Industrial Relations Act Case) ^[100] , is "[t]he modern doctrine". This is the very complaint that the plaintiff makes against the principle, in so far as it claims to express part of Australian constitutional law. He argues that it represents a departure from a carefully formed past doctrine based on a more faithful application of the constitutional text. He submits that it involves the acceptance of an unsettling new approach which was not adequately considered when adopted ^[101] and has not been sufficiently analysed in the cases in which it has subsequently been applied ^[102] .

[68] In obiter remarks, I have earlier accepted the geographical externality principle in cases where it was not criticised or questioned in argument ^[103] . So, it seems, have other present members of this Court. The plaintiff argued that this was the error that should now be corrected ^[104] . The plaintiff said that the holding in Polyukhovich v The Commonwealth (War Crimes Act Case) ^[105] , where, for the first time, a majority of this Court endorsed the geographical externality principle, had been accepted uncritically in subsequent cases. Now, so it was suggested, was the time to pause and reconsider the "modern doctrine" with the benefit of critical analysis, which the Court needed in order to sharpen its federal jurisprudence ^[106] and to correct a dangerous wrong turning.

[69] Various arguments can be mounted to sustain alternative rationales supporting the actual orders of this Court in Polyukhovich, quite apart from the geographical externality principle. Thus, I agree with the reasons of Gummow, Hayne and Crennan JJ that the outcomes in Polyukhovich, and in later cases, can be supported "upon a qualified view of the scope of the external affairs power" ^[107] .

[70] In some of the cases since Polyukhovich, the constitutional validity of the federal law was not contested ^[108] . In one case the impugned principle was not critical to the point ultimately decided ^[109] . In other cases the law in question substantially relied on a treaty, implementation of which is an undisputed basis for a valid federal law relying on s 51(xxix) of the Constitution ^[110] . In other instances there were, as the reasons of Gummow, Hayne and Crennan JJ state, "obvious" and "substantial" connections between Australia and the contested subject matter ^[111] . Thus, in Polyukhovich there was at least one matter of "international concern", being the response of nation states to established instances of crimes of universal jurisdiction, provision for which is arguably also a matter affecting Australia's relations with other states and international organisations and thus a law with respect to "external affairs" upon those grounds ^[112] .

[71] Nevertheless, all this being said, the ratio decidendi to be derived from Polyukhovich depends not on what a majority of this Court might have reasoned in arriving at their conclusions but upon the way in which the majority in fact reasoned. Moreover, the binding rule is to be derived from the legal principles accepted by those members of the Court who, for common reasons, agreed in the Court's orders ^[113] . The principle in Polyukhovich did not emerge out of thin air. It had a number of heralds in the earlier dicta of individual Justices of this Court. These included Jacobs J in New South Wales v The Commonwealth ("the Seas and Submerged Lands Act Case") ^[114] ; Barwick CJ in Robinson v Western Australian Museum ^[115] ; Murphy J in Viro v R ^[116] ; Mason J in Koowarta v Bjelke-Petersen ^[117] ; and Deane J in The Commonwealth v Tasmania (The Tasmanian Dam Case) ^[118] .

[72] Still, the turning point occurred in Polyukhovich when the geographical externality principle gathered support from a majority of the Justices. That majority included Dawson J ^[119] who, before Polyukhovich, had repeatedly expressed the strongest reservation over an expansive interpretation of the "external affairs" power of the Constitution, lest the power, so expanded, be used to disturb the internal federal balances between the Commonwealth and the States beyond that which was clearly required by Australia's participation in the international community and by its relations with other nation states and international organisations.

[73] The consideration that Dawson J in Polyukhovich treated as critical to tipping the balance in favour of acceptance of the geographical externality principle was his view that "[t]he word 'external' is precise and is unqualified" ^[120] . Facts, persons and things lying outside the geographical limits of this country fell within the description "external to it" and thus within the language of s 51(xxix) of the Constitution. It was this reasoning that the plaintiff sought to challenge in these proceedings. In my view, this Court should not brush the challenge aside. We should address it, so far as it is necessary to do so in order to reach an outcome.

[74] A binding rule? From the foregoing it follows that if the "modern doctrine", as propounded by a majority in Polyukhovich, correctly expresses the ambit of s 51(xxix) of the Constitution, the conduct proscribed by ss 50BA and 50BC of the Crimes Act, being with respect to facts, persons or things outside the geographical limits of Australia, falls within the meaning of the phrase "external affairs". This supplies a sufficient "constitutional fact" to sustain the validity of those sections ^[121] . That conclusion, without more, unless its underlying principle is overruled or re-expressed more narrowly, therefore supports the orders announced by this Court. It sustains the constitutional validity of the charges brought against the plaintiff.

[75] The plaintiff did not really contest any of the foregoing. Nor did he suggest that it was possible, in the language of the impugned provisions, to read them down or to re-express them in some way, so as to affect their validity on this hypothesis. For its part, the Commonwealth did not argue for a source of constitutional validity other than s 51(xxix) of the Constitution. Nor, as I have said, was any treaty nominated, the implementation of which would sustain the validity of the contested provisions under that paragraph.

[76] This being the case, it is necessary to consider immediately whether the plaintiff requires, and if so whether he should have, leave to reopen the geographical externality principle as a rule of Australian constitutional law.

Constitutional reargument requires no leave

[77] The supposed requirement of leave: As this Court unanimously said in Lange v Australian Broadcasting Corporation ^[122] , it is not bound by its previous decisions ^[123] . Nor has it laid down any particular rule or rules or set of factors for reopening the correctness of earlier authority ^[124] . Obviously, the Court approaches with caution any suggested reconsideration of a legal principle, including one affecting an understanding of the meaning of the Constitution, which has been decided by a majority of the Justices. Nevertheless, there is no doubt that the Court will re-examine such a principle if it involves a question of "vital constitutional importance" ^[125] and it considers it to be "manifestly wrong" ^[126] . As all members of the Court said in Lange ^[127] :

Errors in constitutional interpretation are not remediable by the legislature ^[128] , and the Court's approach to constitutional matters is not necessarily the same as in matters concerning the common law or statutes.

[78] Various considerations of principle and convenience argue against the reopening of the constitutional rules expressed in Polyukhovich. I will assume that the cases since that decision that have applied the geographical externality principle add nothing of importance to the content of that rule. The rule emerged, as I have shown, from observations and reasoning of individual Justices expressed over more than a decade. Brennan CJ and Toohey J, who expressed a different view in Polyukhovich, nonetheless appear (to the extent necessary) to have endorsed its reasoning without relevant qualification in the Industrial Relations Act Case ^[129] . In consequence, at least to some extent, the principle has been used to sustain particular provisions of federal legislation, the validity of which might be cast in doubt by adoption of a more qualified view of the scope of the external affairs power ^[130] .

[79] Yet are these simply the customary reasons for the exercise of care in giving effect to an opinion about constitutional meaning that is different from that adopted by an earlier majority in this Court? Or is there a procedural barrier of leave that must be overcome, in order to secure consideration by this Court of any submissions critical of past authority about the meaning of the Constitution?

[80] No leave is required: In my view, leave is not required by a party in order to advance arguments contesting a previous determination by the Court as to the meaning of the Constitution. My reasons for that opinion are identical to those stated by Deane J in Evda Nominees Pty Ltd v Victoria ^[131] . As my own reasons have been stated in several cases ^[132] , including recently ^[133] , I will not repeat them now. In the present case, the plaintiff was allowed to present his full arguments. His counsel did so ^[134] . I therefore agree with the reasons of Gummow, Hayne and Crennan JJ that it is unnecessary in this case to embark on a detailed examination of the meaning and application of the majority opinion in Evda ^[135] . That question should be left to a case, if any exists, where it must be determined. This is not such a case.

[81] I therefore proceed directly to the geographical externality principle. It was the primary basis upon which the Commonwealth supported the constitutional validity of the provisions of the Crimes Act challenged by the plaintiff. I accept that a number of arguments can be advanced in favour of the approach expressed in that principle. Many of them are collected, or referred to, in the reasons of Gummow, Hayne and Crennan JJ.

Support for the geographical externality principle

[82] The textual foundation: If the anchor for constitutional interpretation is the text ^[136] , certain textual indications lend support to the "modern doctrine". Section 51(xxix) does not, in its terms, confine itself to "Australia's external affairs". Nor does it expressly limit itself to subjects having some special, and defined, connection with Australia ^[137] . The word "affairs" has a "wide and indefinite meaning". This is what has led advocates of the current approach to conclude that s 51(xxix) ^[138] :

encompass[es] both relationships and things: relationships with or between foreign States and foreign or international organizations or other entities; matters and things which are territorially external to Australia regardless of whether they have some identified connexion with Australia or whether they be the subject matter of international treaties, dealings, rights or obligations.

[83] The broad constitutional grant: The general principle commanding a broad construction of the constitutional text lends additional support to the geographical externality principle unless there is some countervailing consideration that has the effect of cutting down the grant ^[139] . Certainly, the principle as it presently stands involves a very wide view of the constitutional grant of power, encompassing as it does the power to make laws without limitation with respect to facts, persons or things anywhere in the world external to Australia.

[84] Early federal history: As a matter of history, even before federation, the Australian colonies were beginning to take an active part, within the British Empire, in matters of external concern, as for example by involvement in the Universal Postal Union, formed in 1874 ^[140] . Once the Commonwealth was established, the Imperial authorities insisted that the international face of the new federal polity which would be recognised by the Crown was the Commonwealth, and not the States.

[85] This position was illustrated in the Vondel Case that arose in April 1902 concerned with the conduct of South Australian officials dealing with seamen who had deserted from a Dutch ship. The responsible British Minister, Joseph Chamberlain, rebuffed the attempt of the Lieutenant-Governor of South Australia (Sir Samuel Way) to contest the insistence of the British authorities that the State should deal through the Federal Government and its officials ^[141] :

So far as other communities in the Empire or foreign nations are concerned the people of Australia form one political community for which the Government of the Commonwealth alone can speak, and for everything affecting external states or communities, which takes place within its boundaries, that Government is responsible. The distribution of powers between the Federal and State Authorities is a matter of purely internal concern of which no external country or community can take any cognizance. It is to the Commonwealth and the Commonwealth alone that, through the Imperial Government, they must look, for remedy or relief for any action affecting them.

[86] Whilst not specific to the geographical externality principle, the stated approach shows how, from the very beginning of the Commonwealth, federal officials and federal law were expected, within the Empire, to bear the sole responsibility for Australia's relationships ("affairs") with nations, organisations and entities external to Australia.

[87] The external discrimen: Given the necessity to draw lines in respect of the respective lawmaking and other responsibilities of the federal, State and Territory polities, the relevant line that s 51(xxix) of the Constitution provides, suggested by the reference to "affairs" that are "external", is one that begins at the outer limit of the Australian land mass. This, at least, affords an objective discrimen. It refers to the entirety of the rest of the world and, indeed, so far as relevant, any "affairs" that lie beyond that ^[142] .

[88] "Affairs" and "relations": By reference to the juxtaposition of language in s 51(xxx) (with its mention of "the relations of the Commonwealth with the islands of the Pacific" ^[143] ), the suggestion can be made that if it was intended that "external affairs" refer, and refer only, to "relations" of the Commonwealth with other states, that is what would have been said. Instead, the paragraph is more open-textured. It refers to several areas of legal operation including (but not limited to) the implementation of treaties entered with other nation states, organisations or entities ^[144] .

[89] Once it is accepted that the Constitution is not to be confined to meanings that were held, or to applications that were expected, at the time of its adoption in 1900 ^[145] , a functional analysis of its terms lends support to the geographical externality principle.

[90] Responding to external concerns: Clearly, the ambit of international treaties has expanded enormously in recent decades, thereby unquestionably enlarging the denotation of s 51(xxix) ^[146] . It would be a constitutional misfortune if the Australian Constitution were unable effectively to respond to these changes ^[147] . If the legislative power conferred by s 51(xxix) were "inapt to embrace the wide responsibilities and obligations now falling upon the Commonwealth ... [which] needs a more ample grant of legislative power to enable it to conduct a foreign policy that is adequate to ensure its security, and to play its proper part as a member of the ... institutions which contribute at the present time towards the maintenance of international order [and] the welfare of human beings on a world-wide scale" ^[148] , the result would be a serious inconvenience. While such an inconvenience is not determinative, and some inconvenience is inherent in a constitutional instrument expressing limited powers, where the language of the grant suggests a broader view, that view will generally be preferred having regard to the character of the document in which the grant is made ^[149] .

[91] The geographical externality principle largely solves these suggested problems. It avoids the "irksome" ^[150] necessity to seek a formal amendment of the constitutional text. It allows the Constitution, read with today's eyes, to respond to the necessities of the present age. To the extent that the text permits it, Australia, as a nation, should be capable of enacting laws, as other nations can do, with respect to "a place, person, matter or thing [that] lies outside the geographical limits of the country" ^[151] .

[92] Safeguards for the federation: Whatever problems and fearsome possibilities may be conceived, including in the form of a Trojan horse dressed in the colours of "external affairs" that could invade the usual subjects of State powers under the Constitution (the anxiety that most troubled Dawson J ^[152] ), that concern is irrelevant in the case of federal laws addressed to subject matters arising in or affecting facts, persons or things geographically external to Australia ^[153] . In such a case the dangers of constitutional nightmares are thereby avoided, or at least significantly lessened ^[154] . This is so because, substantially, States are only concerned with lawmaking for their own geographical territory and not beyond.

[93] No constitutional "cripple": There are strong reasons of principle for interpreting the Constitution so as to avoid the risk that the Federal Parliament, in terms of its capacity to make laws apt to the contemporary world, would be an international "cripple", with a gap in its lawmaking powers where that gap is not compelled by the constitutional text ^[155] . To the plaintiff's suggestion that any "gap" of this kind could be filled, conformably with the Constitution, by invoking s 51(xxxviii) ^[156] , the Commonwealth responded with a reminder of the cumbersome procedures and practical difficulties in adopting that course and limited instances where that paragraph has been used. That head of constitutional power hardly responds, in an effective way, to the current necessities of national and international governance ^[157] . The Commonwealth invoked the gradual expansion of the recognised powers of legislative extraterritoriality that had accompanied the emergence of Australia as an independent nation and the consequential decline of Imperial inhibitions that had been held applicable in the first decades after federation ^[158] . The geographical externality principle was thus, at once, a response to the changing international context in which the Constitution must now operate and a consequence of the necessity for the Commonwealth to be in a position to respond effectively to that context. So went the main arguments of the Commonwealth.

[94] Resulting difficulties: Despite the powerful arguments of legal authority and also of legal principle and policy supporting the geographical externality principle, the plaintiff made a number of telling criticisms of that approach. It is necessary to take those criticisms into account in deciding whether the principle, now challenged, should be overruled or re-expressed.

Problems of the geographical externality principle

[95] The original expectations: So far as it is relevant, it seems tolerably clear that, in its purest form, the geographical externality principle was not an approach to s 51(xxix) of the Constitution that would have been accepted by the framers of the Constitution or accepted within the setting of the British Empire in the early decades of federation ^[159] . The reasons of Callinan and Heydon JJ demonstrate why this is so ^[160] .

[96] Historically, the very reason for adopting in s 51(xxix) the expression "external affairs", as distinct from "foreign affairs", was to address the comparatively limited grant of legislative power which, in 1900, was thought apt to the Federal Parliament of Australia. Most of the "affairs" relevant to dealings between members of the British Empire were then still the responsibility of the Imperial Government at Westminster. So far as legislating with respect to external relations was concerned, in the early days of federation that remained in large part the continuing responsibility and concern of the Imperial authorities.

[97] "Affairs" and "relations": Allowing that the Constitution must be construed according to what it means now, not what it meant in 1900, the starting point for the plaintiff was suggested by the text. The word "external" in s 51(xxix) was designed to connote relationships and things connected with other nations and with international organisations, both within and outside the British Empire. But for the legal opinion that parts of the British Empire were not "foreign" to each other ^[161] , the words in s 51(xxix) would probably have read "foreign affairs". That, then, was the real subject matter with which (absent the Imperial gloss) the power was intended to deal. Yet once that ambit is understood, it is clear that, in its ordinary Australian meaning, "external affairs" connotes "international relations; activities of a nation arising from its dealings with other nations" ^[162] . The plaintiff urged this Court to return to that meaning, which, he argued, was implicit in the composite idea of "external affairs". Even allowing for a contextual and non-originalist approach to the meaning of s 51(xxix) of the Constitution, the plaintiff submitted that the terms of the paragraph were confined to relationships with foreign nations, a concept that should be restored.

[98] Uniform earlier authority: The plaintiff argued that the adoption of the "modern doctrine" of s 51(xxix) had involved a radical shift from the earlier decisions of this Court concerning the meaning of that paragraph. In R v Burgess; Ex parte Henry ^[163] , counsel explicitly advanced an earlier version of the geographical externality principle. However, it was not accepted by the Court. It is clear enough from the reasons of all members of the Court in Ex parte Henry that they derived much significance for the meaning of the phrase from the word "affairs", used in conjunction with "external". Their Honours' approach was not ostensibly confined to construing the power strictly in accordance with what it had been taken to include in 1900. On the contrary, some of their reasons in that case explicitly traced the gradual emergence of Australia's international personality ^[164] .

[99] Nevertheless, the proposition that s 51(xxix) should be construed as giving power to make laws with respect to matters external to Australia, as such, was not adopted. Latham CJ said that "the substantial subject matter of external affairs" was "[t]he regulation of relations between Australia and other countries, including other countries within the Empire" ^[165] . The Chief Justice considered the phrase as equivalent to a power to make laws with respect to "foreign affairs or relations " ^[166] . A like connotation, equating "affairs" to "the more common expression" of "foreign relations of a State", was accepted by Starke J ^[167] . In his reasons, Dixon J expressed the "evident ... purpose" of the paragraph as being ^[168] :

to authorize the Parliament to make laws governing the conduct of Australians in and perhaps out of the Commonwealth in reference to matters affecting the external relations of the Commonwealth.

[100] Similarly, Evatt and McTiernan JJ, whilst acknowledging that the expression "external affairs" was one "of wide import", said ^[169] :

It is frequently used to denote the whole series of relationships which may exist between States in times of peace or war. It may also include measures designed to promote friendly relations with all or any of the nations.

[101] There is nothing in any of the reasons in Ex parte Henry to lend support to the geographical externality principle. On the contrary, all the reasons appear to accept that "external affairs" is concerned with external relations or relationships of Australia with other nation states. This is the essential meaning that the plaintiff asked this Court to restore.

[102] Meaning of composite expressions: As a textual matter, there is a difficulty in some of the more recent reasoning of members of this Court, so far as they have attempted to explain the expression in s 51(xxix) by splitting up the words and giving separate meaning to "external" and to "affairs" as, arguably, Deane J did in Polyukhovich ^[170] . We now appreciate that this is an inaccurate way of construing composite expressions ^[171] . Each part of such an expression throws light on the meaning of the rest. Each must be taken into account.

[103] The Constitution did not here use the word "foreign" or "external" in association with "matters" ^[172] or "people" ^[173] or "disputes" ^[174] . Still less did the Constitution confer on the Federal Parliament, as the British North America Act of 1867 had done in Canada ^[175] , a legislative power to make laws with respect to the general subject of crime which, with expanding notions of extraterritorial operation of laws, could apply to facts, persons and things occurring in the territory of foreign countries.

[104] It was the context of the phrase considered as a whole, and especially the use of the word "affairs", that led Gibbs CJ in Koowarta ^[176] to favour confining the application of the power in s 51(xxix) of the Constitution to "public business, transactions or matters concerning men or nations collectively" ^[177] . The plaintiff therefore urged that this meaning of the phrase "external affairs" was grounded in more than half a century of this Court's authority. It was more consonant with the evident purpose of the power and its history as appearing in a written Constitution conferring specific and limited powers upon the new Federal Parliament that it created. The plaintiff called for this Court to reverse its departure from the earlier doctrine that had followed the embrace by a minority of the new argument of the Commonwealth in the Seas and Submerged Lands Act Case ^[178] .

[105] Reconciliation with treaty strictness: Whilst the plaintiff accepted, and authority supported, the notion that s 51(xxix) extended beyond the making of treaties and laws to give those treaties effect within Australia, he submitted that a comparatively unbridled power, suggested by the geographical externality principle, was incompatible with a unified notion of the meaning of the paragraph in the Constitution. He argued that it risked unravelling the careful limitations which the Court's previous expositions of s 51(xxix) had established.

[106] Thus, if all that were required to sustain a federal law as valid was some application or relevance to a place, person or thing existing beyond the geographical boundaries of Australia (and especially if, as some dicta proposed, the opinion of the Parliament was to be treated as conclusive as to that connection ^[179] ) the previous insistence of Australian constitutional law upon close conformity between the provisions of a treaty and the federal laws enacted to give such treaty effect ^[180] would be effectively put at nought. Why bother implementing a treaty, the plaintiff asked rhetorically, if the strictures of compliance with the treaty were unnecessary and all that was required to uphold the validity of a federal law was that it could be characterised as one "with respect to" a fact, person or thing geographically external to Australia?

[107] The plaintiff argued that there was an unresolved tension between the geographical externality principle and the principle upholding the constitutional validity of laws based on treaties. The tension could only be resolved by a return to the expositions of s 51(xxix) appearing in Ex parte Henry which, the plaintiff insisted, were already ample enough to permit lawmaking by the Federal Parliament as required for Australia's full participation in relationships with other nations where grounded in an obligation of legal derivation, not a nebulous concern.

[108] Endangering past authority: In elaboration of this last submission, the plaintiff argued that, if the geographical externality principle were correct, it would open the constitutional doors to federal lawmaking with respect to an enormous range of subjects. It would suggest that earlier important decisions of this Court had been wrongly decided.

[109] Thus, if it could be argued that the Communist Party Dissolution Act 1950 (Cth), held not to be a law with respect to "defence" ^[181] , was nonetheless a law with respect to "external affairs" ^[182] because of the world-wide character of the communist threat found by the Federal Parliament to exist beyond Australia and because of the service outside Australia of an Army battalion then operating under the United Nations flag in Korea, the decision in the Communist Party Case ^[183] could have been different. That decision denied the power of the Federal Parliament, by statutory preamble, to find conclusively the existence of the requisite constitutional power ^[184] . There would remain questions of characterisation of the law as one "with respect to" facts, persons or things geographically external to Australia. However, the very large ambit encompassed by the "modern doctrine" is beyond question. Particularly is this so because of the accumulation of matters beyond Australia's borders that are now relevant to the claims of federal lawmakers to make laws having effect within those borders.

[110] Dangers to federalism: The plaintiff also pointed out that it is not accurate to suggest, simply because a place, person or thing is geographically outside the mainland territory of Australia, that it necessarily falls beyond State lawmaking powers, so that any federal laws enacted on the basis of the "modern doctrine" could cause no effective disturbance to the federal-State balance.

[111] States now enjoy substantial powers to enact laws having extraterritorial operation ^[185] . Quite apart from this consideration, as the present case demonstrates, the geographical externality principle, in its most ample application, would certainly authorise federal laws that cut across the enactment of State laws otherwise having operation within the State's own territory. An example may be seen in ss 50DA and 50DB of the Crimes Act providing "[o]ffences of benefiting from, or encouraging, offences against this Part". Those sections, which appear to be directed to travel organisations and like bodies engaged in advertising or promoting child sex tourism, might ordinarily be the subject of State laws, expressing State offences for conduct that would often occur wholly, or substantially, within the borders of the State concerned. The notion which Dawson J appeared to accept in Polyukhovich ^[186] , that there was no danger to the federal-State balance in the geographical externality principle, appears erroneous or at least doubtful in the light of provisions such as ss 50DA and 50DB of the Crimes Act.

[112] In constitutional terms, this particular issue might not be a large problem. However, it cannot be said to be "of no moment" ^[187] , at least in the present case. The plaintiff complained that the Commonwealth had confused the expansion of the extraterritorial operation of a constitutional power that already exists and the expansion of the power itself, beyond its previously acknowledged ambit. The plaintiff urged this Court to return to adherence to that distinction, which, he said, was essential to the scheme of a written federal Constitution that divided power between the several lawmakers in Australia and demanded conformity with its provisions if enacted law were to be valid.

[113] Whilst accepting that the grant of power to the Federal Parliament to make laws for the peace, order and good government of the Commonwealth was expressed in the language of a grant and not in terms of a limitation upon power, the plaintiff argued that the character of the federal Constitution and its purposes required a relevant nexus to exist between the constitutional interests of the Commonwealth and the subject matters to which an enacted federal law was addressed. To the extent that such a law went beyond "external affairs", in the sense of the relationships between nation states (and now relationships with international organisations), it exceeded the proper subject matter of s 51(xxix) of the Constitution. It was therefore invalid.

Alternative validity and the avoidance of problematic issues

[114] Conflicting features of the Constitution: The arguments of the plaintiff in this case have planted a doubt in my mind concerning the geographical externality principle. It is a doubt that was not previously there. I do not accept, as the plaintiff urged, that the Polyukhovich principle should be overruled. However, the plaintiff's submissions call attention to some difficulties in the "modern doctrine" that have not, so far, received sufficient attention from this Court. Such attention may be needed in future cases where the sole constitutional foundation available or propounded for a federal law is that it is made with respect to facts, persons or things external to Australia, without connection otherwise to relationships with other nation states and with international organisations that seem to be implied by the composite expression "external affairs".

[115] In accepting arguments about the scope of federal legislative powers, this Court should be conscious of two important and sometimes conflicting features of the Constitution. The first is the federal character of the polity thereby created. This introduces checks and balances. It divides the power of lawmaking. The divisions are essential to the constitutional design. They are also protective of individual liberties and personal freedoms. Liberties and freedoms can sometimes be endangered by the concentration of power within modern government ^[188] . It may therefore be necessary for this Court to look afresh at its federalism jurisprudence to ensure that it accords with the constitutional text and purpose.

[116] The second feature is the functional capacity of the Constitution to adapt so as to be relevant to a world in which Australia must now operate as an independent nation state -- a world quite different from that of 1900. In that world, there are now so many facts, persons and things external to Australia's geographical borders that, if this is accepted as a valid criterion for sustaining federal laws applicable to facts, persons and things within Australia, there would be almost no limit to the lawmaking power thereby accorded to the Federal Parliament. This is why Brennan J in Polyukhovich ^[189] proposed the need for some additional factor of connection ("nexus" with Australia) to reconcile the second stated feature with the first. The present case suggests to me that the Court needs to revisit Brennan J's reasoning and to elaborate the geographical externality principle further before applying it as an accepted doctrine of Australian constitutional law.

[117] Avoiding problematic issues: Having identified the problems raised by the plaintiff, I can circumvent them in this case. There is, in my view, an alternative foundation for the constitutional validity of the challenged provisions of the Crimes Act. At the risk of being criticised as "unduly timorous or full of self-doubt" ^[190] , I will therefore place the geographical externality principle aside in the present case. I will do so because of what I regard as unresolved difficulties that can be left to another day.

[118] The main alternative bases propounded by the Commonwealth for affirming that the impugned provisions of the Crimes Act constitute laws with respect to "external affairs" were that, on the uncontested materials placed before this Court, they were laws with respect to a "matter of international concern" or laws affecting Australia's external relationships with other nation states and with international organisations. Should either of these arguments be accepted? Do they sustain the provisions of the Crimes Act as valid laws, made under the Constitution?

A matter of international concern

[119] The Commonwealth's submissions: The Commonwealth submitted that, on the basis of the materials received by the Court, the challenged provisions of the Crimes Act were supported by the external affairs power on the footing that they were laws with respect to a "matter of international concern" and thus within the ambit of s 51(xxix) of the Constitution. In past decisions of this Court, several Justices have suggested that the criterion "matter of international concern" describes a proper subject of the "external affairs" of the Commonwealth with respect to which the Federal Parliament is empowered under the Constitution to enact laws ^[191] .

[120] An obvious difficulty with the expression "matter of international concern" is that, at its widest, it could refer to a diverse multitude of topics, lacking any precise definition or meaning ^[192] . As long ago as 1936, Latham CJ recognised the impact on time and space of modern inventions which imposed on nations everywhere (including Australia) a duty to "endeavour to discover means of living together upon practicable terms" ^[193] . In the intervening seventy years, the dimensions of international concern have expanded exponentially.

[121] Evidence in the materials received by this Court in the present case for such "international concern" in respect of sexual offences by foreign nationals against children included:

(1)

The adoption by the General Assembly of the United Nations on 20 November 1989 of the CRC, which had entered into force in 1990 ^[194] ;

(2)

The adoption by the General Assembly of the United Nations on 25 May 2000 of the Optional Protocol to the CRC ^[195] ;

(3)

The appointment by the Secretary-General of the United Nations ^[196] of a Special Rapporteur on the Sale of Children, Child Prostitution and Child Pornography with a mandate to report on those topics to the United Nations Commission on Human Rights. According to an early report by the Special Rapporteur, he welcomed the Australian laws in question in this case as a desirable response to the "transnational sexual exploitation of children" ^[197] ;

(4)

The adoption annually between 1994 and 1997 of resolutions of the United Nations Commission on Human Rights, addressed, amongst other things, to promoting effective international responses to transnational problems of child abuse;

(5)

The signature of particular Memoranda of Understanding in 1997 and 1998 between the Government of Australia and, respectively, the governments of the Philippines and the Fiji Islands, designed to combat child sexual abuse committed by Australian nationals in such countries ^[198] ;

(6)

The enactment by a large number of nation states ^[199] of legislation providing for criminal offences in respect of sexual conduct of their nationals with children outside the national borders of the states concerned; and

(7)

The report published by the House of Representatives Standing Committee on Legal and Constitutional Affairs on the 1994 Bill that introduced into the Crimes Act the provisions the subject of the present proceedings ^[200] .

[122] Against the background of this international and national evidence, the Commonwealth submitted that, whatever the precise ambit of the expression "matter of international concern" might be, the subject of sexual offences against children by Australian nationals in foreign countries was such a matter. It was therefore one that attracted the power to enact laws under s 51(xxix) of the Constitution.

[123] The contrary arguments: In resisting these submissions, the plaintiff repeated many of his earlier arguments to challenge the proposed criterion of "matter of international concern". Once it is accepted that the legislative power with respect to "external affairs" is not confined, as such, to giving effect to binding treaties, the plaintiff acknowledged that some other verbal explanation had to be found to support legislation apt to the full engagement of Australia with the external world, as it now exists.

[124] The plaintiff complained that the suggested criterion of a "matter of international concern" was far too broad to provide a stable and meaningful foundation for the legislative validity of federal laws under s 51(xxix) of the Constitution. On this view, some additional adjectival qualification (such as "real", "genuine", "widespread", "pressing", "established" or "undisputed") had to be deployed to confine the power to an ambit that is clear and proper to its context ^[201] . Alternatively, some other controlling requirement must be introduced, by an alternative verbal formula (such as having a strong "nexus between Australia and the supposed subject of external affairs" or "capable of being reasonably considered to be 'appropriate or adapted'" to addressing the concern ^[202] ) so as to prevent any suggested "matter of international concern" from becoming a means that would destroy the federal character of the Australian Constitution. Certainly, a vastly increased number of matters are now of "international concern". They expand every day. As a criterion of federal law, the concept would therefore be virtually limitless and potentially destructive of Australian federal arrangements.

[125] It is desirable that the Federal Parliament, as the legislature of the national government of Australia, should be able to make laws with respect to matters of international concern to the fullest extent possible as the legislatures of other independent nations may do. However, this is subject to certain qualifications ^[203] . First, such laws must conform to the constitutional requirements stated in an instrument of government of defined and limited powers. Relevantly, they must be laws with respect to "external affairs". Secondly, they must be laws compatible with the divisions of power within the federal polity. Thus, at the very least, they must not, in the guise of being laws with respect to "external affairs", endanger the continued existence and constitutional viability of the States provided for in the Constitution. Thirdly, any such laws must conform to the other requirements of the Constitution, such as those contained in Ch III. The notion that the Federal Parliament in Australia must have plenary and untrammelled power to make laws having some relationship to international or external concerns is not one that is unarguably consistent with such a carefully calibrated, limited and federal constitutional document.

[126] The powers of the Parliament under s 51(xxix) are broad indeed. They are more than ample for most purposes. But they are not and cannot be unlimited. It is the Constitution that limits them. And it is the duty of this Court to uphold the limits.

[127] Conclusion: an undeveloped concept: As with the geographical externality principle, I prefer to put this second argument of the Commonwealth to one side. The suggestion that the constitutional validity of federal laws could be demonstrated by showing that they were made with respect to a "matter of international concern" is still undeveloped in Australia ^[204] . This second argument may, like the first, assign insufficient attention to the appearance of the word "external" in connection with the word "affairs".

[128] It is therefore appropriate to move, finally, to the third argument for validity advanced by the Commonwealth, namely that the contested law is one with respect to the international relationships of Australia with other nation states and international organisations and on that basis is within the external affairs power of the Constitution. I can take this step immediately because, as will appear, I am of the view that it provides a convincing argument for validity. It is an argument that gives full force to the word "affairs" in the constitutional grant. It is also one that is consistent with the long-standing authority of the Court that the power afforded in s 51(xxix) is one concerned at its core with international relationships.

Relationships with nation states and international organisations

[129] The active nationality principle: The understanding of how this third explanation of the ambit of "external affairs" comes about first requires brief mention of a development of international law that occurred during the first century of the Commonwealth. Starting from a general principle that "crime is local" and historically part of the public law of a nation ^[205] , international law might have developed in a way that forbade one nation state making its own laws imposing criminal liability by reference to the conduct of its own nationals within the territory of another nation state ^[206] . Such laws might have been viewed as an infringement by the former nation state of the sovereign rights of the latter.

[130] However, this is not the way international law in fact developed. Instead, the active nationality principle holds that "[t]here is no restriction on the competence in international law of a State to prosecute its own nationals for acts done on foreign territory" ^[207] . In the present case, both Thailand (under the territorial principle) and Australia (under the active nationality principle) could exercise jurisdiction over the plaintiff in full conformity with international law. The international relations of nation states, including those of Australia and Thailand, have developed in accordance with this principle of international law. Indeed, the principle has been clear, at least since the decision of the Permanent Court of International Justice in The Case of the SS "Lotus" ^[208] more than seventy years ago.

[131] Necessarily, a prosecution based on the active nationality principle affects, to some degree, the external relations of Australia with other nation states, notably in this case with Thailand. It does so because both nations assert a right to impose criminal liability by reference to events that happened within the territory of Thailand and which involved alleged conduct with at least one person there who, by inference, is a Thai national or resident. That person and possibly others in Thailand might be called upon to give evidence in a prosecution of the plaintiff. Some might possibly have to come to Australia for that purpose. To this extent, the relations between Australia and a country external to Australia, namely Thailand, are affected, to some degree at least, by the provisions of the Crimes Act whose validity the plaintiff contests.

[132] Once a relationship with another nation state is enlivened (as it necessarily is in the facts of the present case) there is incontestably an "external affair". No doubt or hesitation can arise in the attribution of that phrase to the relationship between states that is inherent in the criminal process envisaged in the present case by the contested provisions of the Crimes Act.

[133] That the provisions intended to enliven the foregoing principle of international law governing the relations between nation states is clear from the terms of s 50AD of the Crimes Act stating that a person must not be charged with an offence of the impugned kind, allegedly committed outside Australia, unless, at the time of the offence, the person was an Australian citizen or a permanent resident of Australia. On the facts contained in the stated case, the plaintiff's Australian citizenship sufficiently enlivens that provision. It afforded a clear connection between the plaintiff and the subject matter of the federal law ^[209] .

[134] On this footing, within this view of the ambit of s 51(xxix) of the Constitution, power existed under that paragraph to enact the law. As the notion of the power of the Federal Parliament to enact laws having extraterritorial operation was enlarged ^[210] , the impediments to the making of such federal law evaporated so long as the relationship with another state was affected by the intended prosecution. Subject to what follows, the effects on the relationship with Thailand (and in other cases with other nation states by the very terms of the contested provisions of the Crimes Act) sufficiently found the validity of the provisions in s 51(xxix) of the Constitution.

[135] Characterisation of the law: There are dicta in the cases that might be understood as suggesting that the courts should defer to the Federal Parliament or the Executive of the Commonwealth in the determination of the relations of Australia with other nation states and with international organisations. Such dicta might suggest that whether such relations sustain laws of the impugned kind is a matter exclusively for the Parliament or the Executive to decide ^[211] . Certainly, in the Australian system of government, the conduct of foreign relations is peculiarly the responsibility of the Executive Government of the Commonwealth ^[212] . It is not, as such, a responsibility of courts.

[136] Nevertheless, the rule of law is a foundational principle of the Australian Constitution. It is inherent in the provisions and purposes of Ch III of the Constitution. This Court cannot surrender, or renounce, its duty of determining the character of a law where the constitutional validity of that law is questioned. The Parliament cannot, by preamble or statutory assertion, exclude the courts from the performance of their constitutional function to decide contested questions as to the meaning and validity of a federal law. This is as true of a law said to be supported by s 51(xxix) of the Constitution as one supported by any other source of constitutional power.

[137] It is not necessary in this case to explore this issue further. The Commonwealth did not rely solely on the language of the Crimes Act, without more. On the contrary, it placed much material before this Court to explain the background and purpose of that law. That material was received as affording constitutional facts upon which the Court was invited to act.

[138] The facts so received unquestionably demonstrated the active involvement of many states, including Australia, in multilateral and bilateral relationships designed to respond effectively to sexual offences by the nationals of those states against children in other states. As well, active debates in the agencies of the United Nations and in other international and regional bodies over the past two decades have concerned the protection of children from sexual conduct on the part of foreign nationals. The material received by the Court affords clear evidence that the subject matter of the challenged provisions of the Crimes Act is (and already was when the law was enacted) one relevant to the external relations of Australia with the international organisations concerned. The participation of many nation states in the activities of such international organisations reinforces the conclusion already reached that the subject of the law is one with respect to the relations of the Commonwealth with nation states other than Australia and thus within s 51(xxix) of the Constitution ^[213] .

[139] Conclusion: validity is sustained: Subject to what follows, this conclusion is sufficient to sustain the constitutional validity of the impugned provisions of the Crimes Act. These provisions are shown to be laws with respect to the relationships (relevantly between Australia and Thailand) affected by the alleged conduct in Thailand of an Australian national. They also affect the relationship between Australia and the United Nations treaty body with responsibility for the implementation of the CRC, a treaty that Australia has ratified. Upon this basis, even on a qualified understanding of the external affairs power, a constitutional foundation for the challenged law is proved. The law, although having operation within Australia, is made with respect to Australia's international relationships. It is thus valid under the Constitution as a law with respect to "external affairs".

The proportionality argument fails

[140] An argument of proportionality: The plaintiff had one last argument. It was not expressed in terms of proportionality. However, that is what, in my view, the argument involved. The plaintiff complained that, even if the constitutional criteria postulated by the Commonwealth for the validity of a federal law on sexual conduct of Australian nationals and permanent residents with children outside Australia were established ^[214] , the impugned provisions of the Crimes Act extended beyond, and differed from, these criteria. The plaintiff argued that the provisions of the law, in their potential field of operation, were invalid because the contested sections of the Crimes Act far overreached the power relied upon. Having regard to the preceding analysis, the question so presented arises for me only in respect of that elaboration of the external affairs power expressed in terms of the relationships of Australia with foreign states and international organisations. Accepting that criterion, is the contested law disproportionate (that is, not "reasonably appropriate and adapted") ^[215] to the exercise of the external affairs power so understood?

[141] In support of this argument, the plaintiff pointed to a number of features of the law. Thus, the relevant provisions of the Crimes Act are not confined (as they might have been) to the implementation of a treaty (such as the Protocol to the CRC) or even, if that would be valid, of any Memorandum of Understanding with Thailand, such as those that have since the enactment of the law been negotiated with the Philippines and the Fiji Islands. The result, so the plaintiff submitted, was a law of general application that imposed Australian criminal sanctions upon conduct occurring overseas, included some conduct that was not criminal in the place where the conduct happened. This was so in the case of Thailand where the age of consent was said to be fifteen years, not sixteen as provided in the Crimes Act of Australia. A fortiori, the law also applied to events involving Australian citizens and permanent residents in countries with substantially lower ages of consent for lawful sexual relations. For instance, Canada adopts a general age of consent of fourteen years for most sexual activity. The same age is said to apply in Albania, Croatia, China, Colombia, Germany, Hungary and Iceland. In some countries, such as Chile and Mexico, the age of consent is said to be twelve years ^[216] .

[142] In these circumstances, the plaintiff asked how criminalising, according to Australian law, conduct that was not criminal where it occurred could ever possibly affect the relationships between nation states or with international organisations? Instead, he submitted, the law represented an illegitimate and over-extensive attempt, beyond the available federal power, to impose Australian cultural norms on activities happening elsewhere in the world. The spectre was presented of an adult Canadian citizen who was an Australian permanent resident being prosecuted on his return to Australia for consensual sexual intercourse or activity lawful in Canada with a person older than fourteen but younger than sixteen years ^[217] . Alternatively, the danger was propounded of the Federal Parliament, supposedly based on Australia's relationships with other nation states or international organisations, enacting laws cutting across different laws enacted by the Australian States on a wide range of matters. Different ages of consent for the purposes of State and Territory criminal laws have long been a feature of Australian legislation ^[218] . The potential use of federal law to undermine the effect of reforms achieved by States and Territories locally was implicit in these submissions.

[143] In default of a provision limiting criminal liability in Australia to a case of equivalent liability in the place where the relevant events occurred ^[219] , the plaintiff argued that the true character of the impugned law was not, as asserted, a law with respect to the external relationships of the Commonwealth with other nation states or international organisations. It was revealed, instead, as a law with respect to a crime involving a matter of postulated domestic concern for which the Federal Parliament had no applicable legislative power under the Constitution.

[144] The law is proportionate: Having regard to the terms of the impugned provisions of the Crimes Act, these arguments should not be accepted in the circumstances of this case. Assuming for present purposes that the constitutional power cannot rely on a criterion of operation merely by reference to geographical externality, and putting aside the suggested criterion of a "matter of international concern", the remaining explanation of s 51(xxix) of the Constitution suffices to sustain the validity of this law. This is so despite apparent discrepancies in the operation of the federal law in particular cases.

[145] True, there is no statutory reason why an instance of the kind postulated involving the hypothesised Canadian citizen could not arise ^[220] . However, in a law of general application applying to acts occurring anywhere other than Australia, such discrepancies are bound to arise in a minority of instances because the Australian federal legislation chooses to adopt a uniform age of consent of sixteen years. The prosecutorial discretion; the judicial conduct of the trial; the common sense of juries; and the exercise of discretions in any punishment that is imposed might respond to disparities of the kind complained of by the plaintiff, were they to arise in practice. Such disparities do not deprive the provisions of the Crimes Act under which the plaintiff has been charged of the constitutional character that sustains their validity upon the basis that I have explained. They remain laws with respect to Australia's relationships with other nation states, in this case Thailand. And for constitutional validity that is enough.

[146] It may be said that, if laws of the present kind were to become common, other countries could impose on people criminal responsibility for acts, not necessarily sexual, done or omitted whilst in Australia, although such acts are perfectly lawful here. However, these are complaints that do not affect the validity of the law contested in this case. There was no suggestion in the materials before this Court that any particular problem had arisen out of the legislation of a very large number of nation states that have already imposed extraterritorial criminal liability upon their nationals for offences against children occurring in foreign jurisdictions ^[221] . The age of sixteen chosen by the Federal Parliament is now the most common age of consent applicable in Australian criminal law ^[222] . In so far as it is relevant to determining the constitutional question of proportionality ("reasonably appropriate and adapted"), and thus the constitutional character of the law, the Australian legislation is neither unusual nor impermissibly overreaching. It appears generally consistent with laws passed by many other nation states. That feature of the law brings it within the external affairs power of the Constitution as that power has long been understood.

[147] The validity of the impugned law can therefore be decided in the present case without reaching any final conclusion on the more difficult constitutional arguments propounded by the Commonwealth: namely "geographical externality" and "matter of international concern". In my view, both of these arguments require further analysis and elaboration to ensure that they are consistent with the essential constitutional postulate of federalism and with the notion inherent in that postulate that the Constitution is one of divided and limited lawmaking powers. Such division is often the best safeguard of limited government and of personal freedom. It is therefore a division to be cherished and safeguarded. When it is at any risk, it behoves this Court to proceed with caution.

Conclusion: the legislation is valid

[148] The provisions of the Crimes Act contested by the plaintiff are valid federal laws. They are sustained by s 51(xxix) of the Constitution. They are validly made with respect to Australia's external relations with other nation states and with international organisations. The provisions of the Crimes Act relevant to this case are proportionate to the exercise of the power so granted to the Federal Parliament for that purpose. That is sufficient to uphold validity. Other suggested arguments advanced by the Commonwealth to support the constitutional validity of the disputed laws do not therefore need to be decided.

[149] The foregoing are my reasons for joining in the orders announced by the Court at the end of argument on 17 November 2005 ^[223] .