BASIC, the Acronym Institute for Disarmament
Diplomacy and Peacerights
Mutual Defence Agreement and the Nuclear Non-Proliferation
Introduction and Summary of Advice
- We are asked to advise BASIC (the British American Security
Information Council), the Acronym Institute for Disarmament
Diplomacy and Peacerights. The question on which our advice is
sought is whether the UK is in breach of the Nuclear
Non-Proliferation Treaty (NPT) by its renewal of the Mutual Defence
Agreement (MDA) with the USA. This raises a number of interlocking
questions of treaty law including the relationship between the two
treaties; interpretation of their terms; the status of the
documents of the Review Conferences; and the meaning of breach of
- In our view, for the reasons set out below, it is strongly arguable
that the renewal of the Mutual Defence Agreement is in breach
of the nuclear Non-Proliferation Treaty.
Applicable Treaty Law
- The principles relating to the law of treaties are
largely codified in the Vienna Convention on the Law of Treaties,
1969, 1155 UNTS (VCLT). The United Kingdom is a party to the VCLT
(ratified 25 June 1971), which came into force 27 January 1980. The
VCLT does not have retroactive effect (article 4) and therefore
does not apply to the original MDA, 1958, although it does so with
respect to renewals subsequent to the coming into force of the
VCLT. The VCLT does not apply to the NPT, which came into force on
5 March 1970.
- However some provisions of the VCLT have been explicitly
accepted as constituting customary international law, including
those on material breach and interpretation. (E.g. Legal
Consequences for States of the Continued Presence of South Africa
in Namibia (South West Africa) Notwithstanding Security Council 276
(1970) 1971 ICJ Rep. 16, 47; Fisheries Jurisdiction Case
(United Kingdom v. Iceland) 1974 ICJ Rep. 3, para. 36). Whether the
provisions on successive treaties constitute customary
international law has not been explicitly addressed, for example by
the International Court of Justice but it is widely accepted that
the Convention 'constitutes the basic framework for any
discussion of the nature and characteristics of treaties.'
(Shaw, International Law, 5th ed. 2003, 811). Brownlie
states that 'certainly those provisions which are not
[declaratory of existing law] constitute presumptive evidence of
emergent rules of general international law.' (Brownlie,
General Principles of International Law, 5th ed. 1998, 608).
The United States is not a party to the VCLT but does accept the
position that it restates much existing law.
- It is first necessary to determine the temporal
relationship between two possibly inconsistent treaties. The MDA
was agreed in 1958, prior to the NPT, which was adopted by the
General Assembly (GA), on 12 June 1968 and came into force on 5
March 1970. However the MDA has been subject to renewal, most
recently in 1994. Renewal of the MDA constitutes a new treaty for
the purposes of domestic law procedures for its adoption. (Senior
Research Clerk, International Affairs and Defence Section, House of
Commons Library: 'The Amendment was a treaty itself, and hence
it was subject to normal treaty law and practices.' (Bundle,
Tab 1, p. 8). It is accordingly also to be regarded as a new treaty
for the purposes of international law.
- The NPT was indefinitely and unconditionally extended by the
Review and Extension Conference on 11 May 1995. This was not a
renewal of the Treaty (thereby implying a new Treaty) but rather an
extension of the existing Treaty in accordance with its own terms:
Article X (2).
- Thus, originally, the NPT succeeded the MDA. However, after
renewal of the MDA it succeeded the NPT.
- The VCLT has provisions on the relationship between successive
treaties on the same subject matter, which are, however, complex
and difficult to apply. Article 30 is the first relevant provision.
This states that
- ... the rights and obligations of States parties to
successive treaties relating to the same subject-matter shall be
determined in accordance with the following paragraphs.
- When a treaty specifies that it is subject to, or that it is
not to be considered as incompatible with, an earlier or later
treaty, the provisions of that other treaty prevail.
- When all the parties to the earlier treaty are parties also
to the later treaty but the earlier treaty is not terminated or
suspended in operation under article 59, the earlier treaty applies
only to the extent that its provisions are compatible with those of
the latter treaty.
- The first question is whether the MDA and the NPT are on the
same subject matter. This is not clear. The expression 'relating
to the same subject matter' 'must be construed strictly.' (I.
Sinclair, The Vienna Convention on the Law of Treaties,
1984, 98). In particular Sinclair states that it 'will not cover
cases where a general treaty impinges indirectly on the content of
a particular provision of an earlier treaty.'
- The MDA rests upon bilateral defence and security through
'cooperation on the uses of atomic energy for mutual defense
purposes'. Its preamble notes that both countries have made
substantial progress in the development of atomic weapons and its
provisions relate to nuclear materials, atomic weapons and atomic
energy. It is based upon the maintenance of nuclear weapons for
security purposes. The NPT is a non-proliferation and disarmament
treaty. It accepts the existence of nuclear weapon states but
ultimately sees disarmament as the goal, with again the focus on
security. It seems that although the approaches are different the
subject matter could be argued to be essentially the same. This
appeared to be the view of certain states, for example Mexico, at
the 1995 Review and Extension Conference (Bundle, Tab 1, p.
- The NPT makes no reference to the MDA (or other bilateral
agreements) so VCLT, article 30 (2) is not applicable. VCLT,
article 30 (3) applies where all the parties to the earlier treaty
are parties to the later treaty, which is the case of the MDA and
the NPT. In such circumstances, unless the first treaty is
terminated (which is not the case in light of its continued
operation and renewal), the earlier treaty remains in force and is
applicable to the extent that its provisions are compatible
with the earlier treaty. Article 30 (3) does not draw any
distinctions between bilateral and multilateral treaties. It is
clear that the parties to a bilateral treaty are bound by their
obligations to the other parties to that multilateral treaty by the
terms of that multilateral treaty.
- After the renewal of the MDA it became the treaty later in
time. The VCLT, article 41 applies to agreements between some but
not all parties to a multilateral treaty that modify the terms of
the multilateral treaty. It states that
1. Two or more of the parties to a multilateral treaty may
conclude an agreement to modify the treaty as between themselves
(a) the possibility of such a modification is provided for by
the treaty; or
(b) the modification in question is not prohibited by the
(i) does not affect the enjoyment by the other parties of
their rights under the treaty or the performance of their
(ii) does not relate to a provision, derogation from which is
incompatible with the effective execution of the object and purpose
of the treaty as a whole.
- Such agreements inter se are therefore permissible only
if they do not affect the enjoyment by other treaty parties of
their rights under the multilateral treaty, or it does not relate
to a provision essential to the effective execution of the object
and purposes of the treaty.
Breach of Treaties
Law of State Responsibility
- Questions of breach of a treaty are determined both by treaty law
and by the principles on state responsibility. The International
Law Commission (ILC), Articles on Responsibility of States for
Internationally Wrongful Acts (GA Res. 56/83, 12 December 2001),
article 12, defines the existence of a breach of an international
obligation as occurring 'when an act of that State is not in
conformity with what is required of it by that obligation, regardless
of its origin or character.' The International Court of Justice
has asserted that such breach includes 'failure to comply with
treaty obligations.' (Gabcikovo-Nagymaros Project (Hungary/Slovakia)
1997 ICJ Reports 7, para. 57). Whether there has been such failure
is determined by asking whether the behaviour in question 'was
in conformity' with the treaty requirements (J. Crawford,
The International Law Commission's Articles on State Responsibility.
Introduction, Text and Commentaries (Cambridge University
Press, 2002) 125).
- It is therefore necessary to determine what action is required
by the NPT and whether the actions of the UK are in conformity with
it. In order to determine this it is necessary to interpret both
the NPT and the MDA, in its latest version.
Principles of Treaty Interpretation
- The VCLT provides the basic principles of treaty
interpretation that are widely accepted as constituting customary
international law (Indonesia/Malaysia case, 2002 ICJ Reports
3, para 37; Libya/Chad case, 1994 ICJ Reports, 6, 21-2;
Qatar/Bahrain case, 1995 ICJ Reports 6, 18). VCLT, article
31 (1) provides that 'A treaty shall be interpreted in good
faith in accordance with the ordinary meaning to be given to the
terms of the treaty in their context and in the light of its object
- There are two events that may be relevant to interpreting the
requirements of the NPT: the initial negotiation history and the
subsequent Review Conferences. The two of course reflect very
different moments in time. The former evidence the intentions of
the original treaty parties and reflect the cold war politics of
the time while the latter reflect the ongoing concerns of the
parties. An important question is what weight should be given to
each of these.
- The Review Conferences take place in accordance with the terms
of the NPT itself. The NPT, Article VIII (2) provides for the
holding of a Conference of Parties to the Treaty 'to review the
operation of this treaty with a view to assuring that the purposes
of the Preamble and the provisions of the Treaty are being
realised.' The provision for a Review Conference is separate from
both the articles for amendment (article VIII (1)) and for
extension. The objective of the Review Conference is thus to
determine whether the purposes of the Treaty (as expressed in the
preamble) and its provisions are being complied with.
- A Declaration of the Review Conference thus does not have formally legally
binding effect (it is not a formal amendment to the Treaty in
the terms of article 8 (1)) but it may have juridical significance
'especially as a source of authoritative interpretation of
the treaty.' (B. Carnahan, 'Treaty Review Conferences', 81
American Journal of International Law (1987) 226, 229).
The VCLT requires that the words of a treaty are interpreted in
their context and in the light of its object and purpose. The
NPT, article VIII (2), makes explicit that the purposes of the
Treaty are to be found in the preamble ('assuring that the
purposes of the preamble...'), in effect bringing the preamble
into the text.
- The preamble of a treaty is in any case part of the treaty's
context for the purpose of interpretation. The VCLT, article 31
(2) states that 'The context for the purpose of the interpretation
of a treaty shall comprise, in addition to the text, including
its preamble and annexes...' Further VCLT, article 31 (3),
specifies that: 'There shall be taken into account, together
with the context: (a) any subsequent agreement between the parties
regarding the interpretation of the treaty or the application
of its provisions; (b) any subsequent practice in the application
of the treaty which establishes the agreement of the parties regarding
its interpretation; ...' A Declaration of a Review Conference
such as that adopted by consensus would fall within the wording
of article 31 (3) (a) and is thus an appropriate source of interpretation
of the obligations of the NPT.
- Reference to the use that can be made of a treaty's travaux
preparatoires (preparatory work) is made in VCLT, article 32.
Article 32 states that 'Recourse may be had to supplementary
means of interpretation, including the preparatory work of the
treaty and the circumstances of its conclusion, in order to confirm
the meaning resulting from the application of article 31, or to
determine the meaning when the interpretation according to article
31: (a) leaves the meaning ambiguous or obscure; or (b) leads to a
result which is manifestly absurd or unreasonable.'
- Article 32 makes preparatory work relevant only as a secondary
source of interpretation, to be referred to when there is
ambiguity, or where the approach under article 31 leads to a
manifestly absurd or unreasonable result. This is a lesser status
than that accorded to the preamble and any subsequent agreement
between the parties by article 31. This is confirmed by the heading
given to each of the two articles. Article 31 is headed 'General
rule of interpretation' while article 32 is headed
'Supplementary means of interpretation.'
- Accordingly, greater weight should be given to the Declarations
of the Review Conference than to the preparatory work of the NPT in
determining the scope of obligations under the Treaty text
Determination of Breach
- The relevant part of NPT, article 1 provides that:
'Each nuclear weapon State Party to the Treaty undertakes not
to transfer to any recipient whatsoever nuclear weapons or other
nuclear explosive devices indirectly or indirectly...'
- A number of commentators have argued that the MDA does not violate
the NPT, article 1. The MDA, article V (B), is on its face in
conformity with article 1 in that it states that 'there will be
no transfer by either party of atomic weapons' (but makes no mention
of nuclear explosive devices). The NPT has no definition section
so neither 'nuclear weapons' nor 'nuclear explosive
devices' are defined. The article may be seen as permissive
rather than prohibitive in that it lists only what is not allowed.
In the words of Dean Rusk: 'The treaty deals only with what
is prohibited, not what is permitted.'
- Dean Rusk asserted that the NPT 'does not deal with, and
therefore does not prohibit, transfer of nuclear delivery vehicles,
or delivery systems, ... so long as such transfer does not involve
bombs or warheads. It does not deal with allied consultations
and planning on nuclear defense so long as no transfer of nuclear
weapons or control over them results.' (Senate Foreign Relations
Committee, Hearings on the Treaty on the non-Proliferation of
Nuclear Weapons' 90th Cong. 2nd Session, 5-6 (1968)).
- The drafters 'intended to exclude nuclear delivery and military
propulsion systems' and to limit the term 'nuclear weapon'
to 'only one aspect of nuclear weapons capability, namely the
warhead or bomb.' (M. Willrich, 'The Treaty on Non-proliferation
of Nuclear Weapons: Nuclear Technology Confronts World politics',
77 Yale Law Journal (1968) 1447, 1464). Article 1 does
not prohibit the transfer of delivery systems such as missiles
or aircraft that are merely capable of being equipped with nuclear
warheads, nor the transfer of a nuclear reactor intended to provide
the propulsion system for a submarine. This interpretation adopted
by the US 'has not been challenged, at least publicly by other
parties to the NPT.' (J. Woodliffe, 'Nuclear Weapons and Non-Proliferation:
The Legal Aspects', in I. Pogany (ed.), Nuclear Weapons and
International Law, 1987, 84, 89). This comment was made in
1987 before the Review and Extension Conference 1995 and the Review
Conference 2000. It raises the question whether other states parties
are bound by this interpretation through their acquiescence and
failure to protest. The failure to get any final document agreed
in 1995 that incorporated objections to the interpretation of
article 1 raised in the draft report from Main Committee 1 (Bundle,
Tab 1, p. 25) is consistent with that view.
- Assistance that does not amount to actual direct or indirect
transfer of nuclear weapons or nuclear explosive devices (depending
upon the interpretation given to those words) does not therefore
contravene the wording of article 1. The prohibition in article
1 on nuclear weapons states assisting, encouraging or inducing
the manufacture or acquisition of nuclear weapons or other nuclear
explosive devices applies only to non-nuclear states. 'This
leaves open the possibility that nuclear-weapon states could "assist"
each other in ways that do not amount to transfer, again leading
commentators to suggest that article 1 is not breached by the
MDA.' (M. Willrich, 'The Treaty on Non-proliferation of Nuclear
Weapons: Nuclear Technology Confronts World politics', 77 Yale
Law Journal (1968) 1447, 1477).
- However, obligations under the NPT, article VI, need also to
be considered. Article VI states: 'Each of the parties to the
Treaty undertakes to pursue negotiations in good faith on effective
measures relating to cessation of the nuclear arms race at an
early date and to nuclear disarmament and on a treaty on general
and complete disarmament under strict and effective control.'
- Article VI is the 'only treaty provision in which NWS have
undertaken a legal obligation to negotiate nuclear disarmament
agreements.' (M. Marin Bosch, The Non-Proliferation Treaty
and its Future', in L. Boisson de Chazournes and P. Sands, eds),
International Law, the International Court of Justice and Nuclear
Weapons, 1999, 375, 388). 'It is important to note that
the NPT is the only existing international treaty under which
the major nuclear powers are legally committed to disarmament.'
(T. Rauf, 'Nuclear Disarmament: Review of Article VI', in J. Simpson
and D. Howlett (eds), The Future of the Non-Proliferation Treaty,
1995, 66,67). It is 'the single most important provision of
the treaty, however, from the standpoint of long-term success
or failure of its goal of proliferation prevention'. (E. Firmage,
'The Treaty on the Non-Proliferation of Nuclear Weapons', 63 American
Journal of International Law (1969) 711, 732).
- India, Brazil, Scandinavian states, Canada, the then UAR and
Germany 'brought strong pressure upon the Co-chairmen to obtain
some statement within the treaty concerning nuclear disarmament.'
(E. Firmage, 'The Treaty on the Non-Proliferation of Nuclear Weapons',
63 American Journal of International Law (1969) 711, 733).
The August 1967 draft included reference to 'cessation of the
arms race' in its preamble. An earlier version of Article VI was
included within the body of the Revised Draft Treaty on Nonproliferation
of Nuclear Weapons, 18 January 1968. Sweden in particular insisted
on strengthening Article VI by broadening the commitment of the
nuclear weapon states (NWS) to seek disarmament agreements. In
the GA debate on the draft treaty further objections were made
to the lack of 'tangible commitment to nuclear disarmament by
NWS (for example by Brazil, India). Article VI was further revised
before its inclusion in the adopted Treaty. (E. Firmage, 'The
Treaty on the Non-Proliferation of Nuclear Weapons', 63 American
Journal of International Law (1969) 711, 716-721).
- The drafting history is important as it shows the linkage between
the commitment of non-nuclear states to non-proliferation and
the obligations on nuclear weapon states to nuclear disarmament.
Article VI was an integral part of the NPT package, not just an
'add-on'. Its importance to the objectives of the treaty is indicated
by the Preamble, paras 8-12. These include the 'intention to
achieve at the earliest possible date the cessation of the nuclear
arms race' and 'to undertake effective measures in the direction
of nuclear disarmament.'
- The 1995 Review and Extension Conference did not lead to the
'specific commitments towards genuine nuclear disarmament within
a concrete time frame' sought by a number of non-nuclear states
leading to the conclusion from one commentator that in 1995 'it
ceased to be a tool for nuclear disarmament.' (M. Marin Bosch,
'The Non-Proliferation Treaty and its Future', in L. Boisson de
Chazournes and P. Sands, eds, International Law, the International
Court of Justice and Nuclear Weapons, 1999, 379, 383).
- However the Final Document of the Review Conference 2000 (without
the leverage of non-nuclear weapon states in threatening non-extension)
reiterated the importance of the commitment to disarmament in
a number of its statements. For example in its Review of the operation
of the treaty the Conference noted the overwhelming majority of
States entered into their legally binding commitments not to acquire
nuclear weapons 'in the context, inter alia of the corresponding
legally binding commitments by the nuclear weapon states to nuclear
disarmament in accordance with the Treaty.' (Bundle, Tab 6, p.
3). Further the Conference reaffirmed that the 'strict observance'
of the provisions of the Treaty remains central to achieving the
shared objectives of preventing under any circumstances, the further
proliferation of nuclear weapons and preserving the Treaty's vital
contribution to peace and security.
- The Review Conference also agreed practical steps for systematic
and progressive efforts to implement NPT, Article VI: Step 6 'An
unequivocal undertaking by the NWS to accomplish total elimination
of their nuclear arsenals leading to nuclear disarmament under
article VI'. Step 9: Steps by all NWS 'leading to nuclear disarmament
in a way that promotes international stability ... increased transparency
by the NWS with regard to the nuclear weapons capabilities ...
concrete agreed measures to further reduce the operational status
of nuclear weapons systems.' (Bundle tab 6, p. 18).
- Thus the importance of Article VI to the objects and purposes
of the NPT is shown both by the negotiation history of the NPT
and by the reaffirmation of its significance by the 2000 Review
Conference. The Review Conference also emphasised that strict
observance of the NPT is required, that is observance with both
the letter and spirit of its articles.
- In addition in 1996 the ICJ in an Advisory Opinion unanimously
There exists an obligation to pursue in good faith and
bring to a conclusion negotiations leading to nuclear disarmament
in all its aspects under strict and effective control.
(Legality of the Threat or Use of Nuclear Weapons,
1996 ICJ Rep. Para. 105 (2) (F)).
- In the view of one commentator the Court has broadened the scope
of Article VI from being just a 'code of conduct'. Marin
Bosch states that 'The Court recognises that the provisions
of Article VI... go beyond mere obligations of conduct - to pursue
nuclear disarmament negotiations in good faith - and actually
involve an obligation of result, i.e., to conclude those negotiations.'
(M. Marin Bosch, The Non-Proliferation Treaty and its Future',
in L. Boisson de Chazournes and P. Sands, eds), International
Law, the International Court of Justice and Nuclear Weapons,
- Assertions about the importance of renewal of the MDA are not
in conformity with the obligations of Article VI and the commitments
made in the 2000 Review Conference. The MDA itself, as amended
1994, article 3 bis is directed towards 'improving the
UK's state of training and operational readiness' (article
3 (1) (2)) and 'improving the UK's atomic weapon design, development
or fabrication capability.' (article 3 (3) bis). These
both imply continuation and indeed enhancement of the nuclear
programme, not progress towards its discontinuation.
- Similarly, in his Message to Congress on the renewal of the
MDA, President Bush wrote 'that the United Kingdom intends
to continue to maintain viable nuclear forces... I have concluded
that it is in our interest to continue to assist them in maintaining
a credible nuclear force.' (Bundle, Tab 3). It is noticeable
that the only reference to compliance with the law in this statement
is to statutory, not treaty, law.
- This statement for the partner in the MDA is indicative of the
UK's position that is supported by statements from the UK. For
example the Strategic Defence Review, New Chapter July 2002 states
that 'The UK's nuclear weapons have a continuing use as a means
of deterring major strategic military threats.' (Bundle tab 1,
p. 18). The vital importance of the MDA for the advancement of
the UK's nuclear weapons programme and has been recognised in
the UK. Statements referring to how it has enabled 'significant
advances in several areas of research' and how joint activity
under the Agreement is to the 'benefit of the nuclear weapons
programme on both sides of the Atlantic' are on the AWE website.
(Bundle tab 1, p. 15). Another conclusion states that 'Together
with the support of data and technical exchanges under the US/UK
1958 Mutual Defence Agreement ... the United Kingdom was able
to put warhead systems into service with far fewer nuclear tests
than any other Nuclear Weapon States.' (Experimental Hydrodynamics,
Discovery Issue 5, AWE July 2002, bundle tab 1, p. 16).
- These statements make it clear that the MDA is important to
the UK's ongoing nuclear programme. It is strongly arguable that
this is not in accordance with the obligations under Article VI
or the assertion of the 2000 Review Conference to take steps leading
to nuclear disarmament.
Breach of Treaty under the VCLT
- The analysis has proceeded under the definition of
breach provided by the International Law Commission's Articles on
State Responsibility. The issue of breach is also included in the
VCLT. However the VCLT deals only with 'material' breach. The
Articles on State Responsibility provisions are not limited to
material breach and are applicable to any lesser breach of a
- Thus in addition to determining whether the UK is in breach of
the obligations of the NPT, we should also consider whether such
behaviour amounts to material breach.
- The VCLT, article 60 (3) defines a material breach as occurring
in one of two ways: 'A material breach of a treaty, for the
purposes of this article, consists in: (a) a repudiation of the
treaty not sanctioned by the present Convention; or (b) the
violation of a provision essential to the accomplishment of the
object or purpose of the treaty.'
- The UK has not repudiated the NPT and has indeed reaffirmed it. For example
the Foreign Secretary, stated on 3 February, 2004 that 'The
UK remains committed to the NPT which we regard as the cornerstone
of the global non-proliferation and disarmament regime.' (Bundle
tab 1, p. 18).
- Therefore, if there is any material breach it must be under
VCLT, article 60 (3) (b), that is whether there is behaviour that
violates a provision 'essential to the accomplishment of the
object or purpose of the treaty.' The objects of the NPT as
spelled out in the preamble include the 'prevention of the wider
dissemination of nuclear weapons' and 'to undertake
effective measures in the direction of nuclear disarmament'.
Both articles I and VI are essential to the accomplishment of these
objects and, as discussed above, are integrally linked. The
non-nuclear weapon states required commitments from the nuclear
weapon states as part of their willingness to accept non-nuclear
Consequences of Breach
Under the International Law Commission's Articles on State
Responsibility. Article 1, '[a]n internationally wrongful act of
a State [including breach of a treaty] entails the international
responsibility of that State.' Article 30 spells out the
consequences of violation:
The State responsible for the internationally wrongful act is
under an obligation:
(a) To cease that act, if it is continuing;
(b) To offer appropriate assurances and guarantees of
non-repetition, if circumstances so require.
- The following articles spell out requirements for compensation.
The VCLT provides further consequences of material breach. Under
VCLT, article 60 (2) determination of material breach of a
multilateral treaty 'entitles: (a) the other parties by
unanimous agreement to suspend the operation of the treaty in whole
or in part or to terminate it either: (i) in the relations between
themselves and the defaulting State, or (ii) as between all the
parties.' However performance and compliance are what is
required, not termination of the Treaty either as between all
parties or between other parties and the UK.
Effect of non-renewal of the MDA
- The MDA does not provide for renewal but rather
article XII states that it will remain in force until
'terminated by Agreement of both parties' (with particular
provisions for article II). Article III bis has time limits
written into it (31 December 2004). Accordingly if this provision
is not terminated it will automatically lapse. The new (renewed
treaty) would not come into force until ratified by both parties
and accordingly the existing treaty would remain in force until
then but without the various transfers provided for in article III
bis 'prior to 31 December 2004.' Article II may be
terminated unilaterally on one year's notice to the other
Use of the Royal Prerogative
- The use of the royal prerogative for the renewal of
the MDA is appropriate. This is because the power to make treaties,
including their renewal, is vested in the Crown as part of the
Royal Prerogative and is exercised, according to constitutional
convention, on the advice of ministers. 'The Crown retains its
hitherto undoubted powers to make and ratify treaties.' (A.
McNair, The Law of Treaties, 1961, 68; Oppenheim's
International Law, 1992, vol 1, 1226-8).
- The Crown cannot change domestic law without the consent of
Parliament. This is why treaties do not create rights and
obligations within the domestic legal system unless and until they
are introduced into it by Act of Parliament: R v Lyons
 1 AC 976. However, the consent of Parliament is not required
to make or ratify treaties so as to render them binding at the
level of international law.
- With respect to the application of the Ponsonby Rule, which has
since the 1920s established a practice of laying a draft treaty
before Parliament for 21 days before it is ratified by the Crown,
this is not binding as a matter of law but is of obvious importance
to Parliament itself. It provides a sound basis for members of
Parliament to call for debate on the renewal of the MDA, especially
since, in accordance with our advice, it is strongly arguable that
renewal would breach the UK's obligations under the NPT.
- If we can be of further assistance, those instructing us should
not hesitate to contact us again.
Rabinder Singh QC Professor Christine Chinkin
20 July 2004
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