The effect of that subsection is that a person, whatever his nationality, who agrees in England to a course of conduct which will involve the offence of murder abroad may be prosecuted here for the offence of conspiracy to murder even although the murder itself would not have been triable in this country. It re-enacted a provision to the same effect in section 4 of the Offences against the Person Act 1861, which it in part repealed: see Schedule 13 to the Act of 1977. Section 4 of the Act of 1861 was in these terms:

 "All persons who shall conspire, confederate, and agree to murder any person, whether he be a subject of Her Majesty or not, and whether he be within the Queen's Dominions or not, and whosoever shall solicit, encourage, persuade, or endeavour to persuade, or shall propose to any person, to murder any other person, whether he be a subject of Her Majesty or not, and whether he be within the Queen's Dominions or not, shall be guilty of a misdemeanour, and being convicted thereof shall be liable, at the discretion of the court, to be kept in penal servitude for any term not more than ten and not less than three years,--or to be imprisoned for any term not exceeding two years, with or without hard labour."

So the conduct which is alleged against Senator Pinochet in charge 9 - that between 1 January 1975 and 31 December 1976 he was a party to a conspiracy in Spain to murder someone in Spain - is an offence for which he could, unless protected by immunity, be extradited to Spain under reference to section 4 of the Act of 1861, as it remained in force until the relevant part of it was repealed by the Act of 1977. This is because his participation in the conspiracy in Spain was conduct by him in Spain for the purposes of section 2(1)(a) of the Extradition Act 1989.

The conduct which is alleged against him in charge 4 is that he was a party to a conspiracy to murder, in furtherance of which about four thousand people were murdered in Chile and in various countries outside Chile including Spain. It is implied that this conspiracy was in Chile, so I would hold that this is not conduct by him in Spain for the purposes of section 2(1)(a) of Act of 1989. The question then is whether it is an extra-territorial offence within the meaning of section section 2(1)(b) of that Act.

 A conspiracy to commit a criminal offence in England is punishable here under the common law rules as to extra-territorial conspiracies even if the conspiracy was formed outside England and nothing was actually done in this country in furtherance of the conspiracy: Somchai Liangsiriprasert v. Government of the United States of America [1991] 1 A.C. 225. In that case it was held by the Judicial Committee, applying the English common law, that a conspiracy to traffic in a dangerous drug in Hong Kong entered into in Thailand could be tried in Hong Kong although no act pursuant to that conspiracy was done in Hong Kong. Lord Griffiths, delivering the judgment of the Board, said at p. 251C-D:

 "Their Lordships can find nothing in precedent, comity or good sense that should inhibit the common law from regarding as justiciable in England inchoate crimes committed abroad which are intended to result in the commission of criminal offences in England."

In Regina v. Sansom [1991] 2 Q.B. 130 the appellants had been charged with conspiracy contrary to section 1 of the Criminal Law Act 1977, which does not in terms deal with extra-territorial conspiracies. The Court of Appeal rejected the argument that the principle laid down in Somchai referred only to the common law and that it could not be applied to conspiracies charged under the Act of 1977. Taylor L.J. said, at p. 138B that it should now be regarded as the law of England on this point.

As Lord Griffiths observed in Somchai at p. 244C, it is still true, as a broad general statement, that English criminal law is local in its effect and that the criminal law does not concern itself with crimes committed abroad. But I consider that the common law of England would, applying the rule laid down in Somchai, also regard as justiciable in England a conspiracy to commit an offence anywhere which was triable here as an extra- territorial offence in pursuance of an international convention, even although no act was done here in furtherance of the conspiracy. I do not think that this would be an unreasonable extension of the rule. It seems to me that on grounds of comity it would make good sense for the rule to be extended in this way in order to promote the aims of the convention.

Prior to the coming into force of the Suppression of Terrorism Act 1978, a conspiracy which was formed outside this country to commit murder in some country other than England in pursuance of which nothing was done in England to further that conspiracy would not be punishable in England, as it was not the intention that acts done in pursuance of the conspiracy would result in the commission of a criminal offence in this country. The presumption against the extra-territorial application of the criminal law would have precluded such conduct from being prosecuted here. Section 4(1) of the Act of 1978 gives the courts of the United Kingdom jurisdiction over a person who does any act in a convention country which, if he had done that act in a part of the United Kingdom, would have made him guilty in that part of the United Kingdom of an offence mentioned in some, but not all, of the paragraphs of Schedule 1 to that Act. Murder is one of the offences to which that provision applies. But that Act, which was passed to give effect to the European Convention on the Suppression of Terrorism of 27 January 1977, did not come into force until 21 August 1978: S.I. 1978 No. 1063. And Chile is not a convention country for the purposes of that Act, nor is it one of the non-convention countries to which its provisions have been applied by section 5 of the Act of 1978. Only two non-convention countries have been so designated. These are the United States (S.I. 1986 No. 2146) and India (S.I. 1993 No. 2533).

Applying these principles, the only conduct alleged against Senator Pinochet as conspiracy to murder in charge 4 for which he could be extradited to Spain is that part of it which alleges that he was a party to a conspiracy in Spain to commit murder in Spain prior to 21 August 1978. As for the allegation that he was a party to a conspiracy in Spain or elsewhere to commit murder in a country which had been designated as a convention country after that date, the extradition request states that acts in furtherance of the conspiracy took place in France in 1975, in Spain in 1975 and 1976 and in the United States and Portugal in 1976. These countries have now been designated as countries to which the Suppression of Terrorism Act 1978 applies. But the acts which are alleged to have taken place there all pre-date the coming into force of that Act. So the extra-territorial jurisdiction cannot be applied to them.

The alleged offences of attempted murder in Italy are not, as such, offences for which Senator Pinochet could be extradited to Spain under reference to section 2(1)(a) of the Act of 1989 because the alleged conduct did not take place in Spain and because he is not of Spanish nationality. But for their date they would have been offences for which he could have been extradited from the United Kingdom to Spain under reference to section 2(1)(b), on the grounds, first, that murder is now an extra-territorial offence under section 4(1)(a) of the Suppression of Terrorism Act 1978 as it is an offence mentioned in paragraph 1 of Schedule 1 to that Act, Italy has been designated as a convention country (S.I. 1986 No. 1137) and, second, that an offence of attempting to commit that offence is an extra-territorial offence under section 4(1)(b) of the Act of 1978. But the attempted murders in Italy which are alleged against Senator Pinochet are said to have been committed on 6 October 1975. As the Act of 1978 was not in force on that date, these offences are not capable of being brought within the procedures laid down by that Act.

Finally, to complete the provisions which need to be reviewed under this heading, mention should be made of an amendment which was made to Schedule 1 to the Suppression of Terrorism Act 1978 by section 22 of the Criminal Justice Act 1988, which includes within the list of offences set out in that schedule the offence of conspiracy. That section appears in Part 1 of the Act of 1988, most of which was repealed before having been brought into force following the enactment of the Extradition Act 1989. But section 22 was not repealed. It was brought into force on 5 June 1990: S.I. 1990 No. 1145. It provides that there shall be added at the end of the schedule a new paragraph in these terms:

 "21. An offence of conspiring to commit any offence mentioned in a preceding paragraph of this Schedule."

At first sight it might seem that the effect of this amendment was to introduce a statutory extra-territorial jurisdiction in regard to the offence of conspiracy, wherever the agreement was made to participate in the conspiracy. But this offence does not appear in the list of offences in that Schedule in respect of which section 4(1) of the Suppression of Terrorism Act 1978 gives jurisdiction, if committed in a convention country, as extra-territorial offences. In any event section 22 was not brought into force until 5 June 1990: S.I. 1990 No. 1145. This was after the last date when Senator Pinochet is alleged to have committed the offence of conspiracy.

Torture and conspiracy to torture

Torture is another of those offences, wherever the act takes place, which is deemed by section 22(6) of the Extradition Act 1989 to be an offence committed within the territory of any other state against whose law it is an offence. This provision gives effect to the Torture Convention of 10 December 1984. But section 134 of the Criminal Justice Act 1988 also gave effect to the Torture Convention. It made it a crime under English law for a public official or a person acting in an official capacity to commit acts of both physical and mental torture: see subsection (3). And it made such acts of torture an extra-territorial offence wherever they were committed and whatever the nationality of the perpetrator: see subsection (1). Read with the broad definition which the expression "torture" has been given by Article 1 of the Convention and in accordance with ordinary principles, the offence which section 134 lays down must be taken to include the ancillary offences of counselling, procuring, commanding and aiding or abetting acts of torture and of being an accessory before or after the fact to such acts. All of these offences became extra-territorial offences against the law of the United Kingdom within the meaning of section 2(2) of the Extradition Act 1989 as soon as section 134 was brought into force on 29 September 1988.

Section 134 does not mention the offence of conspiracy to commit torture, nor does Article 1 of the Convention, nor does section 22(6) of the Extradition Act 1989. So, while the courts of the United Kingdom have extra-territorial jurisdiction under section 134 over offences of official torture wherever in the world they were committed, that section does not give them extra-territorial jurisdiction over a conspiracy to commit torture in any other country where the agreement was made outside the United Kingdom and no acts in furtherance of the conspiracy took place here. Nor is it conduct which can be deemed to take place in the territory of the requesting country under section 22(6) of the Act of 1989.

However, the general statutory offence of conspiracy under section 1 of the Criminal Law Act 1977 extends to a conspiracy to commit any offence which is triable in England and Wales. Among those offences are all the offences over which the courts in England and Wales have extra-territorial jurisdiction, including the offence under section 134 of the Act of 1988. And, for reasons already mentioned, I consider that the common law rule as to extra- territorial conspiracies laid down in Somchai Liangsiriprasert v. Government of the United States of America [1991] 1 A.C. 225 applies if a conspiracy which was entered into abroad was intended to result in the commission of an offence, wherever it was intended to be committed, which is an extra-territorial offence in this country. Accordingly the courts of this country could try Senator Pinochet for acts of torture in Chile and elsewhere after 29 September 1988, because they are extra-territorial offences under section 134 of the Act of 1988. They could also try him here for conspiring in Chile or elsewhere after that date to commit torture, wherever the torture was to be committed, because torture after that date is an extra-territorial offence and the courts in England have jurisdiction over such a conspiracy at common law.

Torture prior to 29 September 1989

Section 134 of the Criminal Law Act 1988 did not come into force until 29 September 1988. But acts of physical torture were already criminal under English law. Among the various offences against the person which would have been committed by torturing would have been the common law offence of assault occasioning actual bodily harm or causing injury and the statutory offence under section 18 of the Offences against the Person Act 1861 of wounding with intent to cause grievous bodily harm. A conspiracy which was entered into in England to commit these offences in England was an offence at common law until the common law offence was replaced on 1 December 1977 by the statutory offence of conspiracy in section 1 of the Criminal Law Act 1977 which remains in force and available. As I have said, I consider that a conspiracy which was entered into abroad to commit these offences in England would be triable in this country under the common law rule as to extra- territorial conspiracies which was laid down in Somchai Liangsiriprasert v. Government of the United States of America [1991] 1 A.C. 225 if they were extra-territorial offences at the time of the alleged conspiracy.

However none of these offences, if committed prior to the coming into force of section 134 of the Criminal Justice Act 1988, could be said to be extra-territorial offences against the law of the United Kingdom within the meaning of section 2(2) of the Extradition Act 1989 as there is no basis upon which they could have been tried extra-territorially in this country. The offences listed in Schedule 1 to the Suppression of Terrorism Act 1978 include the common law offence of assault and the statutory offences under the Offences against the Person Act 1861. But none of these offences are included in the list of offences which are made extra- territorial offences if committed in a convention country by section 4(1) of the Extradition Act 1989. So the rule laid down in Somchai cannot be applied to any conspiracy to commit these offences in any country outside England, as it would not be an extra-territorial conspiracy according to English law. Senator Pinochet could only be extradited to Spain for such offences under reference to section 2(1)(a) of the Act of 1989 if he was accused of conduct in Spain which, if it occurred in the United Kingdom, would constitute an offence which would be punishable in this country. Section 22(6) of the Act of 1989 is of no assistance, because torture contrary to the Torture Convention had not yet become an offence in this country.

None of the charges of conspiracy to torture and none of the various torture charges allege that Senator Pinochet did anything in Spain which might qualify under section 2(1)(a) of the Act of 1989 as conduct in that country. All one can say at this stage is that, if the information presented to the magistrate under section 9(8) of the Act of 1989 in regard to charge 4 were to demonstrate (i) that he did something in Spain prior to 29 September 1988 to commit acts of torture there, or (ii) that he was party to a conspiracy in Spain to commit acts of torture in Spain, that would be conduct in Spain which would meet the requirements of section 2(1)(a) of that Act.

Torture after 29 September 1989

The effect of section 134 of the Criminal Justice Act 1988 was to make acts of official torture, wherever they were committed and whatever the nationality of the offender, an extra- territorial offence in the United Kingdom. The section came into force two months after the passing of the Act on 29 September 1988, and it was not retrospective. As from that date official torture was an extradition crime within the meaning of section 2(1) of the Extradition Act 1989 because it was an extra-territorial offence against the law of the United Kingdom.

The general offence of conspiracy which was introduced by section 1 of the Criminal Law Act 1977 applies to any offence triable in England and Wales: section 1(4). So a conspiracy which took place here after 29 September 1988 to commit offences of official torture, wherever the torture was to be carried out and whatever the nationality of the alleged torturer, is an offence for which Senator Pinochet could be tried in this country if he has no immunity. This means that a conspiracy to torture which he entered into in Spain after that date is an offence for which he could be extradited to Spain, as it would be an extradition offence under section 2(1)(a) of the Act of 1989. But, as I have said, I consider that the common law of England would, applying the rule laid down in Somchai Liangsiriprasert v. Government of the United States of America [1991] 1 A.C. 225, also regard as justiciable in England a conspiracy to commit an offence which was triable here as an extra-territorial offence in pursuance of an international convention, even although no act was done here in furtherance of the conspiracy. This means that he could be extradited to Spain under reference to section 2(1)(b) of the Act of 1989 on charges of conspiracy to torture entered into anywhere which related to periods after that date. But, as section 134 of the Act of 1988 does not have retrospective effect, he could not be extradited to Spain for any conduct in Spain or elsewhere amounting to a conspiracy to commit torture, wherever the torture was to be carried out, which occurred before 29 September 1988.

The conduct which is alleged against Senator Pinochet under the heading of conspiracy in charge 4 is not confined to the allegation that he was a party to an agreement that people were to be tortured. Included in that charge is the allegation that many people in various countries were murdered after being tortured in furtherance of the conspiracy that they would be tortured and then killed. So this charge includes charges of torture as well as conspiracy to torture. And it is broad enough to include the ancillary offences of counselling, procuring, commanding, aiding or abetting, or of being accessory before or after the fact to, these acts of torture. Ill-defined as this charge is, I would regard it as including allegations of torture and of conspiracy to torture after 29 September 1988 for which, if he has no immunity, Senator Pinochet could be extradited to Spain on the ground that, as they were extra-territorial offences against the law of the United Kingdom, they were extradition crimes within the meaning of section 2(1) of the Act of 1989.

What is the effect of the qualification which I have just mentioned, as to the date on which these allegations of torture and conspiracy to torture first became offences for which, at the request of Spain, Senator Pinochet could be extradited? In the circumstances of this case its effect is a profound one. It is to remove from the proceedings the entire course of such conduct in which Senator Pinochet is said to have engaged from the moment he embarked on the alleged conspiracy to torture in January 1972 until 29 September 1988. The only offences of torture and conspiracy to torture which are punishable in this country as extra-territorial offences against the law of the United Kingdom within the meaning of section 2(2) of the Act of 1989 are those offences of torture and conspiracy to torture which he is alleged to have committed on or after 29 September 1988. But almost all the offences of torture and murder, of which there are alleged to have been about four thousand victims, were committed during the period of repression which was at its most intense in 1973 and 1974. The extradition request alleges that during the period from 1977 to 1990 only about 130 such offences were committed. Of that number only three have been identified in the extradition request as having taken place after 29 September 1988.

Of the various offences which are listed in the draft charges only charge 30, which refers to one act of official torture in Chile on 24 June 1989, relates exclusively to the period after 29 September 1988. Two of the charges of conspiracy to commit torture extend in part over the period after that date. Charge 2 alleges that Senator Pinochet committed this offence during the period from 1 August 1973 to 1 January 1990, but it does not allege that any acts of torture took place in furtherance of that conspiracy. Charge 4 alleges that he was party to a conspiracy to commit torture in furtherance of which acts of murder following torture were committed in various countries including Spain during the period from 1 January 1972 to 1 January 1990. The only conduct alleged in charges 2 and 4 for which Senator Pinochet could be extradited to Spain is that part of the alleged conduct which relates to the period after 29 September 1988.

Although the allegations of conspiracy to torture in charge 2 and of torture and conspiracy to torture in charge 4 must now be restricted to the period from 29 September 1988 to 1 January 1990, the fact that these allegations remain available for the remainder of the period is important because of the light which they cast on the single act of torture alleged in charge 30. For reasons which I shall explain later, I would find it very difficult to say that a former head of state of a country which is a party to the Torture Convention has no immunity against an allegation of torture committed in the course of governmental acts which related only to one isolated instance of alleged torture. But that is not the case which the Spanish judicial authorities are alleging against Senator Pinochet. Even when reduced to the period from 29 September 1988 until he left office as head of state, which the provisions for speciality protection in section 6(4) of the Extradition Act 1989 would ensure was the only period in respect of which the Spanish judicial authorities would be entitled to bring charges against him if he were to be extradited, the allegation is that he was a party to the use of torture as a systematic attack on all those who opposed or who might oppose his government.

The extradition request states that between August 1977, when the National Intelligence Directorate (DINA) was dissolved and replaced by the National Intelligence Bureau (CNI), the Directorate of Communications of the Militarised Police (DICOMCAR) and the Avenging Martyrs Commando (COVERMA), while engaged in a policy of repression acting on orders emanating from Augusto Pinochet, systematically performed torture on detainees (Bound Record, vol. 2, pp. 314-315). Among the methods which are said to have been used was the application of electricity to sensitive parts of the body, and it is alleged that the torture sometimes led to the victim's death. Charge 30 alleges that the victim died after having been tortured by inflicting electric shock. The two victims of an incident in October 1988, which is mentioned in the extradition request but is not the subject of a separate count in the list of draft charges, are said to have shown signs of the application of electricity after autopsy. It appears that the evidence has revealed only these three instances after 29 September 1988 when acts of official torture were perpetrated in pursuance of this policy. Even so, this does not affect the true nature and quality of those acts. The significance of charges 2 and 4 may be said to lie in the fact that they show that a policy of systematic torture was being pursued when those acts were perpetrated.

I must emphasise that it is not our function to consider whether or not the evidence justifies this inference, and I am not to be taken as saying that it does. But it is plain that the information which is before us is capable of supporting the inference that the acts of torture which are alleged during the relevant period were of that character. I do not think that it would be right to approach the question of immunity on a basis which ignores the fact that this point is at least open to argument. So I consider that the óKóóKargument that Senator Pinochet has no immunity for this reduced period is one which can properly be examined in the light of developments in customary international law regarding the use of widespread or systematic torture as an instrument of state policy.

Charges which are relevant to the question of immunity

The result of this analysis is that the only charges which allege extradition crimes for which Senator Pinochet could be extradited to Spain if he has no immunity are: (1) those charges of conspiracy to torture in charge 2, of torture and conspiracy to torture in charge 4 and of torture in charge 30 which, irrespective of where the conduct occurred, became extra-territorial offences as from 29 September 1988 under section 134 of the Criminal Justice Act 1988 and under the common law as to extra territorial conspiracies; (2) the conspiracy in Spain to murder in Spain which is alleged in charge 9; (3) such conspiracies in Spain to commit murder in Spain and such conspiracies in Spain prior to 29 September 1988 to commit acts of torture in Spain, as can be shown to form part of the allegations in charge 4.

So far as the law of the United Kingdom is concerned, the only country where Senator Pinochet could be put on trial for the full range of the offences which have been alleged against him by the Spanish judicial authorities is Chile.

State immunity

Section 20(1)(a) of the State Immunity Act 1978 provides that the Diplomatic Privileges Act 1964 applies, subject to "any necessary modifications", to a head of state as it applies to the head of a diplomatic mission. The generality of this provision is qualified by section 20(5), which restricts the immunity of the head of state in regard to civil proceedings in the same way as Part I of the Act does for diplomats. This reflects the fact that section 14 already provides that heads of state are subject to the restrictions in Part I. But there is nothing in section 20 to indicate that the immunity from criminal proceedings which Article 31.1 of the Vienna Convention as applied by the Act of 1964 gives to diplomats is restricted in any way for heads of state. Section 23(3), which provides that the provisions of Parts I and II of the Act do not operate retrospectively, makes no mention of Part III. I infer from this that it was not thought that Part III would give rise to the suggestion that it might operate in this way.

It seems to me to be clear therefore that what section 20(1) did was to give statutory force in the United Kingdom to customary international law as to the immunity which heads of state, and former heads of state in particular, enjoy from proceedings in foreign national courts. Marcos and Marcos v. Federal Department of Police [1990] 102 I.L.R 198, 203 supports this view, as it was held in that case that the Article 39.2 immunity was available under customary international law to the former head of state of the Republic of the Philippines.

The question then is to what extent does the immunity which Article 39.2 gives to former diplomats have to be modified in its application to former heads of state? The last sentence of Article 39.2 deals with the position after the functions of the diplomat have come to an end. It provides that "with respect to acts performed by such person in the exercise of his functions as a member of the mission, immunity shall continue to subsist." It is clear that this provision is dealing with the residual immunity of the former diplomat ratione materiae, and not with the immunity ratione personae which he enjoys when still serving as a diplomat. In its application to a former head of state this provision raises two further questions: (1) does it include functions which the head of state performed outside the receiving state from whose jurisdiction he claims immunity, and (2) does it include acts of the kind alleged in this case - which Mr. Alun Jones Q.C. accepts were not private acts but were acts done in the exercise of the state's authority?

As to the first of these two further questions, it is plain that the functions of the head of state will vary from state to state according to the acts which he is expected or required to perform under the constitution of that state. In some countries which adhere to the traditions of constitutional monarchy these will be confined largely to ceremonial or symbolic acts which do not involve any executive responsibility. In others the head of state is head of the executive, with all the resources of the state at his command to do with as he thinks fit within the sphere of action which the constitution has given to him. I have not found anything in customary international law which would require us to confine the expression "his functions" to the lowest common denominator. In my opinion the functions of the head of state are those which his own state enables or requires him to perform in the exercise of government. He performs these functions wherever he is for the time being as well as within his own state. These may include instructing or authorising acts to be done by those under his command at home or abroad in the interests of state security. It would not be right therefore to confine the immunity under Article 39.2 to acts done in the receiving state. I would not regard this as a "necessary modification" which has to be made to it under section 20(1) of the Act of 1978.

As to the second of those questions, I consider that the answer to it is well settled in customary international law. The test is whether they were private acts on the one hand or governmental acts done in the exercise of his authority as head of state on the other. It is whether the act was done to promote the state's interests - whether it was done for his own benefit or gratification or was done for the state: United States v. Noriega (1990) 746 F.Supp. 1506, 1519-1521. Sir Arthur Watts Q.C. in his Hague Lectures, The Legal Position in International Law of Heads of States, Heads of Governments and Foreign Ministers (1994-III) 247 Recueil des cours, p. 56, said : "The critical test would seem to be whether the conduct was engaged in under colour of or in ostensible exercise of the head of state's public authority." The sovereign or governmental acts of one state are not matters upon which the courts of other states will adjudicate: I Congresso del Partido [1983] A.C. 244, 262C per Lord Wilberforce. The fact that acts done for the state have involved conduct which is criminal does not remove the immunity. Indeed the whole purpose of the residual immunity ratione materiae is to protect the former head of state against allegations of such conduct after he has left office. A head of state needs to be free to promote his own state's interests during the entire period when he is in office without being subjected to the prospect of detention, arrest or embarrassment in the foreign legal system of the receiving state: see United States v. Noriega, p. 1519; Lafontant v. Aristide (1994) 844 F.Supp. 128, 132. The conduct does not have to be lawful to attract the immunity.

It may be said that it is not one of the functions of a head of state to commit acts which are criminal according to the laws and constitution of his own state or which customary international law regards as criminal. But I consider that this approach to the question is unsound in principle. The principle of immunity ratione materiae protects all acts which the head of state has performed in the exercise of the functions of government. The purpose for which they were performed protects these acts from any further analysis. There are only two exceptions to this approach which customary international law has recognised. The first relates to criminal acts which the head of state did under the colour of his authority as head of state but which were in reality for his own pleasure or benefit. The examples which Lord Steyn gave [1998] 3 W.L.R. 1456, 1506B-C of the head of state who kills his gardener in a fit of rage or who orders victims to be tortured so that he may observe them in agony seem to me plainly to fall into this category and, for this reason, to lie outside the scope of the immunity. The second relates to acts the prohibition of which has acquired the status under international law of jus cogens. This compels all states to refrain from such conduct under any circumstances and imposes an obligation erga omnes to punish such conduct. As Sir Arthur Watts Q.C. said in his Hague Lectures, page 89, note 198, in respect of conduct constituting an international crime, such as war crimes, special considerations apply.

But even in the field of such high crimes as have achieved the status of jus cogens under customary international law there is as yet no general agreement that they are outside the immunity to which former heads of state are entitled from the jurisdiction of foreign national courts. There is plenty of source material to show that war crimes and crimes against humanity have been separated out from the generality of conduct which customary international law has come to regard as criminal. These developments were described by Lord Slynn of Hadley [1998] 3 W.L.R. 1456, 1474D-H and I respectfully agree with his analysis. As he said, at p. 1474H, except in regard to crimes in particular situations where international tribunals have been set up to deal with them and it is part of the arrangement that heads of state should not have any immunity, there is no general recognition that there has been a loss of immunity from the jurisdiction of foreign national courts. This led him to sum the matter up in this way at p. 1475B-E:

 "So it is necessary to consider what is needed, in the absence of a general international convention defining or cutting down head of state immunity, to define or limit the former head of state immunity in particular cases. In my opinion it is necessary to find provision in an international convention to which the state asserting, and the state being asked to refuse, the immunity of a former head of state for an official act is a party; the convention must clearly define a crime against international law and require or empower a state to prevent or prosecute the crime, whether or not committed in its jurisdiction and whether or not committed by one of its nationals; it must make it clear that a national court has jurisdiction to try a crime alleged against a former head of state, or that having been a head of state is no defence and that expressly or impliedly the immunity is not to apply so as to bar proceedings against him. The convention must be given the force of law in the national courts of the state; in a dualist country like the United Kingdom that means by legislation, so that with the necessary procedures and machinery the crime may be prosecuted there in accordance with the procedures to be found in the convention."

That is the background against which I now turn to the Torture Convention. As all the requirements which Lord Slynn laid out in the passage at p. 1475B-E save one are met by it, when read with the provisions of sections 134 and 135 of the Criminal Justice Act 1988 which gave the force of law to the Convention in this country, I need deal only with the one issue which remains. Did it make it clear that a former head of state has no immunity in the courts of a state which has jurisdiction to try the crime?

The Torture Convention and Loss of Immunity

The Torture Convention is an international instrument. As such, it must be construed in accordance with customary international law and against the background of the subsisting residual former head of state immunity. Article 32.2 of the Vienna Convention, which forms part of the provisions in the Diplomatic Privileges Act 1964 which are extended to heads of state by section 20(1) of the Sovereign Immunity Act 1978, subject to "any necessary modifications", states that waiver of the immunity accorded to diplomats "must always be express". No modification of that provision is needed to enable it to apply to heads of state in the event of it being decided that there should be a waiver of their immunity. The Torture Convention does not contain any provision which deals expressly with the question whether heads of state or former heads of state are or are not to have immunity from allegations that they have committed torture.

But there remains the question whether the effect of the Torture Convention was to remove the immunity by necessary implication. Although Article 32.2 says that any waiver must be express, we are required nevertheless to consider whether the effect of the Convention was necessarily to remove the immunity. This is an exacting test. Section 1605(a)(1) of the United States Federal Sovereignty Immunity Act provides for an implied waiver, but this section has been narrowly construed: Siderman de Blake v. Republic of Argentina (1992) 965 F.2d 699, p. 720; Princz v. Federal Republic of Germany (1994) 26 F.3d 1166, p. 1174; Argentine Republic v. Amerada Hess Shipping Corporation (1989) 109 S.Ct. 683, p. 693. In international law the need for clarity in this matter is obvious. The general rule is that international treaties should, so far as possible, be construed uniformly by the national courts of all states.

The preamble to the Torture Convention explains its purpose. After referring to Article 5 of the Universal Declaration of Human Rights which provides that no one shall be subjected to torture or other cruel, inhuman or degrading treatment and to the United Nations Declaration of 9 December 1975 regarding torture and other cruel, inhuman or degrading treatment or punishment, it states that it was desired "to make more effective the struggle against torture and other cruel, inhuman or degrading treatment or punishment throughout the world". There then follows in Article 1 a definition of the term "torture" for the purposes of the Convention. It is expressed in the widest possible terms. It means "any act by which severe pain or suffering, whether physical or mental, is intentionally inflicted" for such purposes as obtaining information or a confession, punishment, intimidation or coercion or for any reason based on discrimination of any kind. It is confined however to official torture by its concluding words, which require such pain or suffering to have been "inflicted by or at the instigation of or with the consent or acquiescence of a public official or other person acting in an official capacity".