Traditional view: it’s automatically incorporated
LORD MANSFIELD CJ in Triquet v Bath (1764) who cites LORD TALBOT CJ in the Barbuit’s Case (1736): “The law of nations in its full extent was part of the law of England”.
O’KEEFE says Lord Mansfield CJ’s suggestion was “baseless”, and that the term “the law of nations” used by his Lordship has a very different meaning at the time Mansfield LCJ was using it.
Duke of Brunswick v. King of Hanover
LORD DENNING MR in Trendtex v Central Bank of Nigeria (1977): “As the court have given effect to changes in CIL without any Act of Parliament, it follows that the rules of international law, as existing from time to time, do form part of English law, provided that they are not inconsistent with Acts of Parliament. If that were not the case, the courts could not recognise changes in the norms of international law.”
BLACKSTONE (1765), who was counsel in an early English case in which Lord Mansfield approved of his position on his subject, argued: ‘the Law of Nations . . . is here adopted in its full extent by the common law, and is held to be a part of the law of the land. And those acts of parliament, which have from time to time been made to enforce this universal law, or to facilitate the execution of its decisions, are not to be considered as introductive of any new rule, but merely as declaratory of the old fundamental constitutions of the kingdom; without which it must cease to be part of the civilised world.’
LAUTERPACHT spots an ambiguity in Blackstone’s words noting that ‘. . . it is controversial whether in laying down the rule that international law was part of the law of the land Lord Mansfield and Blackstone were giving expression to an actual rule of English law at the time, or whether they were formulating a principle whose rationality appeared to them obvious and irrefutable regardless of its historical accuracy.’
CAPPS: it may be that incorporation is right, but Blackstone’s comments do not conclusively settle the matter. This is because he does not tell us whether customary international law can be applied by English courts because it is incorporated by virtue of its reasonableness or because of the existence of a norm in English law which operates as a formal source of the substantive or material international legal obligations.
SALES AND CLEMENT: Blackstone was not confronted with a legal world in which these rules [of international law] were being changed or added to by processes external to the law-making arrangements set out in the constitution of the state. Further, he was writing at a time before the full development of democratic legal theory in the 19th and 20th centuries, and before the full development of credible democratic credentials of Parliament with the expansion of the franchise over that period. These twin developments call into question whether Blackstone's position can continue to be accepted in modern times.
COLLIER notes an often-overlooked argument in favour of the incorporation doctrine: when, as directed by the choice of law rules of private international law, or the conflict of laws, an English court is called upon to decide a case by applying the law of a foreign country, France for example, that law has the status of fact. Like any other fact it has to be proved by evidence and, like some other kinds of fact, by expert witnesses, should its existence or content be contested. Rules of public international law are not treated thus. They have the status of rules of law. Of course, the existence of a rule or its content may be in doubt and the court will have to be satisfied in this respect, but this is done by the argument of counsel, not the evidence of witnesses, and judicial notice will be taken of the rules of public international law.
Is it really the traditional view?
As Lord Hoffmann in [Re McKerr (2004)] points out, international law and domestic law are very different sources” which create obligations belonging to “different legal systems”, owed by “different parties”, have “different contents” and “different mechanisms for enforcement”. This begs the question—are the courts really simply “automatically” giving effect to CIL in English law? Or is something more subtle happening?
Given that international law, as Sawer [(1984) International Law in Australia] and Lord Hoffmann in [Re McKerr (2004)] point out, relates to fundamentally different rights and obligations from domestic law, O’Keefe [(2008) BYIL] seems to correctly suggest that the courts are not in fact giving effect to CIL directly (or “automatically”). Rather, in the cases where they have given effect to CIL (typically concerning immunities, less often piracy and in two instances, angary) they are creating an equivalent common law rule based on the status of CIL when it deems it appropriate to develop the common law in light of international law. As such O’Keefe suggests that what the courts are doing should not be viewed as a doctrine of “incorporation” as Lord Denning MR in [Trendtex v Central Bank of Nigeria (1977)] suggests, but rather as a “doctrine of judicial transformation”.
It is submitted that O’Keefe’s view is correct. The function of international law is fundamentally distinct from domestic law, and so it is not quite correct to suggest that CIL “automatically” is part of English law. This is simply not logical as international law and domestic law serve different functions and the former cannot simply apply in the context of the latter—it needs to be adapted and transposed into the domestic context.
Academic criticism of the traditional view:
O’KEEFE: in the many historical and modern cases where the court invoked the principle that CIL is automatically part of the domestic common law, they ended up not applying this principle because parliamentary legislation addressed the issue.
SALES AND CLEMENT: CIL has only ever been successfully applied in domestic courts concerning piracy, protection of diplomats, and sovereign immunity. COLLIER: the occasions on which rules of customary international law fall to be applied by English courts are relatively few. The cases that have been discussed are to a large extent concerned with limited types of situation. Most of them are to do with immunities of foreign States and governments and of diplomatic agents or with territorial waters. That is to say, they concern questions of jurisdiction.
O’KEEFE says it is ‘striking’ that in R v. Jones (Margaret) two of the substantive judgments decline explicitly to affirm the accuracy of the proposition that CIL is automatically part of English law. He says that in recognising the proposition that CIL is part of English law only where the constitution permits, the Lords acknowledge that the relationship between IL and English law is ‘inescapably dualist’.
SALES AND CLEMENT: (1) it is possible that a state may become bound by a rule of CIL without having assented to it in any way, since under the modern statement of the relevant principle all that is required in practice is that a large majority of states accept the binding force of the rule in question; and, more generally, the legitimacy of the law-making process in relation to the formation of CIL is itself open to question. (2) a rule of CIL is identified by reference to the practice of states, which may consist in the actions of the executive arm of a state without reference to legislative involvement. Breach of SOP.
Newer cases: it’s a source and guides the development of the common law
Lord Mance in Keyu (2015): “Common law judges on any view retain the power and duty to consider how far customary international law on any point fits with domestic constitutional principles and understandings. Domestic courts face a policy issue in deciding whether to recognise and enforce a rule of international law…The presumption…is that customary international law, once established, can and should shape the common law, whenever it can do so consistently with domestic constitutional principles, statutory law and common law rules which the courts can themselves sensibly adapt without it being, for example, necessary to invite Parliamentary intervention or consideration.”
Lord Bingham in R v. Jones (Margaret) (2007): ‘there seems to be truth in Brierly’s contention… that international law is not a part, but is one of the sources, of English law.’
LORD HOFFMANN in R v. Jones (Margaret): ‘I say nothing about the reception into English law of rules of international law which may affect rights and duties in civil law.’
Suggests that while new crimes clearly cannot be automatically incorporated, perhaps there can be automatic incorporation in other areas of the law.
LORD MANCE also said that ‘it is unnecessary to consider the recognition or reception of international law in the context of civil law.’
Academic support for this view: Collier and Brierly
Limits to the role of CIL
It’s a source only where this wouldn’t contravene constitutional principle:
LORD MANCE in Keyu: “speaking generally, in my opinion, the presumption when considering any such policy issue is that CIL, once established, can and should shape the common law, whenever it can do so consistently with domestic constitutional principles, statutory law and common law rules which the courts can themselves sensibly adapt without it being, for example, necessary to invite Parliamentary intervention or consideration.”
R (on the application of Freedom and Justice Party) v Secretary of State for...