I. INTRODUCTION
States that wish to become parties to a multilateral treaty, but are reluctant to be bound by the treaty in full, invariably resort to reservations. Reservations serve to modify or exclude the legal effects of treaty provisions. They are often deployed to either limit the obligations undertaken by the reserving State or to enable the discharge of treaty obligations by equivalent means.Footnote 1
Contemporary international law governing reservations developed from the International Court of Justice's (ICJ) 1951 Reservations to the Genocide Convention Advisory Opinion (Genocide Convention Advisory Opinion).Footnote 2 The Genocide Convention Advisory Opinion laid down important principles for the operation of reservations including, inter alia, that unanimous acceptance of reservations is not required unless expressly stipulated, and that reservations are illegal if they contravene the object and purpose of a treaty.Footnote 3 These elements were subsequently incorporated into the Vienna Convention on the Law of Treaties (Vienna Conventions),Footnote 4 the single most important instrument on the law of treaties, forming the bedrock of international treaty law today. The introduction of these concepts, however, also gave rise to some of the most complex questions in international law.Footnote 5 Among the deeply perplexing questions are: whether the object and purpose test is an objective or subjective test;Footnote 6 whether dispute settlement mechanisms have the competence to assess reservations;Footnote 7 whether an acceptance may save a reservation that is otherwise incompatible with the object and purposes of a treaty;Footnote 8 and whether impermissible reservations are severable.Footnote 9 These questions arose as a result of a paradigm shift away from a contractual model of treaty relations, under which the decision whether a reservation could have any legal significance at all depended solely on the reactions of its addressees.
In 1993, the International Law Commission (ILC) committed itself to the monumental task of clarifying some of the aforementioned uncertainties.Footnote 10 Through 18 years of extensive research and deliberations, in 2011, the ILC produced the Guide to Practice on Reservations to Treaties and its Commentary (Guide to Practice and Commentary).Footnote 11 Among the notable suggestions proposed, one remarkable view concerned how the ILC chose to conceptualize reservations as ‘unilateral acts’.Footnote 12 At first sight, this may seem redundant—after all, reservations are widely accepted as ‘unilateral statements’ as defined in the Vienna Convention.Footnote 13 On second thoughts, however, this conceptualization might be problematic. If a reservation is a unilateral act, which body of rules—the law of unilateral acts or the law of treaties—should govern the use and effect of reservations? Given that the law on unilateral acts and the law of treaties are widely considered distinct areas of international law, in that they address very different contexts and concerns, characterizing reservations as unilateral acts appears inappropriate.
Surprisingly, the ILC's answer to the above question is that the law of unilateral acts should indeed govern certain aspects of reservations.Footnote 14 This is a conclusion that is seemingly inconsistent with the approach taken in the ILC's 2006 Guiding Principles Applicable to Unilateral Declarations of States Capable of Creating Legal Obligations (2006 Guiding Principles on Unilateral Declarations), which categorically excluded reservations from its ambit of study.Footnote 15 One rationale is that a reservation does not only attach to an international agreement but also attaches to the manifestation of consent to be bound by the international agreement, the latter of which comes very close to a ‘unilateral act’ in international law.Footnote 16 Nevertheless, the ILC argued that when applying the laws of unilateral acts on reservations, rules and principles must be interpreted in the light of the specific circumstances of reservations, ie that reservations necessarily arise in the context of an existing international agreement.Footnote 17 This implies that, while rules governing the above aspects of reservations may derive from principles applicable to unilateral acts, such rules should also be interpreted in the context of treaties.Footnote 18 As shall be demonstrated in this article, the result is an innovative ‘hybrid’ approach where the law of unilateral acts and the law of treaties overlap in the context of reservations. The former is applicable when consent is at issue (eg when determining the scope of a reservation and the consequences of its invalidity), while the latter continues to govern, inter alia, formal procedures, including the termination, withdrawal, and suspension of reservations.
This article examines the ILC's arguments and explains in detail how the ILC attempted to resolve contemporary questions on reservations by conceptualizing them as unilateral acts. After highlighting the significance of the approach taken by the ILC to existing debates, this article further attempts to predict the potential influence of this approach on future international law and practice.
Section II of the article provides an overview of the debates surrounding rules applicable to reservations, setting out the context of the present article. Section III will revisit the law of unilateral acts. It will identify features of reservations that resemble unilateral acts recognized in international law. Section IV examines how the Guide to Practice approaches reservations and analyses the consequences of viewing reservations as unilateral acts in terms of their timing of existence, justiciability, and interpretation. In particular, it explains how rules concerning reservations may be different when they are considered ‘non-autonomous’ unilateral acts. This section will also attempt to predict the effects of the ILC's emphasis on the unilaterality of reservations on the future practice of reservations. It explains why the approach adopted by the Guide to Practice will render the effects of reservations more predictable. It also explains why, instead of eroding mutual consent, the stress in ‘unilaterality’ paradoxically better preserves the mutual consent of States in the practice of reservations.
II. THE ORIGINS OF THE DEBATES CONCERNING APPLICABLE RULES ON RESERVATIONS
Directly inspired from the notion of contract, customary international law prior to the League of Nations dictated that a reservation must be accepted by all parties to a treaty before the reserving State could itself become a party. This is often referred to as the principle of unanimity.Footnote 19 Under this principle, whether a reservation was valid and whether it was to have any effect at all depended solely on the addressee State(s). Yet, during the period of the League of Nations, State practice concerning reservations to multilateral treaties revealed serious inconsistencies. While the League Secretariat (later the Secretary-General of the United Nations) adopted the principle of unanimity, the Pan-American Union (later the Organization of American States) allowed a reserving State to become a party to a multilateral treaty vis-à-vis non-objecting States.Footnote 20
In 1948, the adoption of the Convention on the Prevention and Punishment of the Crime of Genocide by the United Nations General Assembly (UNGA) prompted questions over the admissibility of reservations.Footnote 21 This resulted in a request to the ICJ for an advisory opinion. With the bench divided, the majority in the Genocide Convention Advisory Opinion adopted a ‘flexible approach’ by allowing a reserving State to become a party to the Convention as long as the reservation is not incompatible with the object and purpose of the Convention; it is with reference to the object and purpose of the treaty that States shall furnish their objections.Footnote 22 The rationale for this approach was that States should not be prevented from becoming a party to the Convention if their reservations were only marginal.Footnote 23 It was thought that this would increase the participation of States in ratifying multilateral treaties—thus enhancing the process of the codification of international law through the use of treatiesFootnote 24—while maintaining a sufficient level of treaty integrity to enable treaties to operate effectively.Footnote 25
The Genocide Convention Advisory Opinion had an enduring impact on the development of the law of treaties. Articles 19–23 of the Vienna Convention, which govern applicable rules on reservations, incorporated concepts expounded previously by the ICJ, including, most prominently, the object and purpose test. Yet, the notion also gave rise to deeply troubling questions. In particular, Article 19(c) provided that a State may not formulate a reservation if the reservation is incompatible with the object and purpose of the treaty.Footnote 26 Meanwhile, Articles 20(4)(a) and 21(1)(a) respectively provided that ‘[a]cceptance by another contracting State of a reservation constitutes the reserving State a party to the treaty’Footnote 27 and that such an acceptance ‘[m]odifies for the reserving State in its relations with that other party the provisions of the treaty to which the reservation relates to the extent of the reservation’.Footnote 28 Therefore, what would be the effect of the acceptance of a reservation that may reasonably be said to be incompatible with the object and purpose of the treaty? If the object and purpose test is essentially a subjective test, ie a matter wholly for the accepting State to decide, then the acceptance of a reservation pursuant to Article 20(4) suffices to render a reservation valid regardless of its prima facie incompatibility. On the other hand, if the object and purpose test is essentially an objective test, then Article 19(3) should trump Article 20(4)—even though this would give rise to another question: which international judicial/quasi-judicial bod(ies) shall have the authority to pronounce on the invalidity of such reservations?Footnote 29 Moreover, since a reservation objected to by another State on grounds of incompatibility would not automatically preclude the reserving State from becoming a party to the multilateral treaty,Footnote 30 what would be the legal consequence of a reservation subsequently found incompatible (assuming there is a competent third party to adjudicate on the permissibility of reservations)? These unresolved questions form a core part of the very enigma that continues to puzzle international lawyers today.
III. Construing Reservations as Unilateral Acts
Construing reservations as unilateral acts is an altogether different way of imagining reservations. A unilateral act in international law refers to an unequivocal expression of will formulated publicly by one State to other State(s) or international organization(s), committing to acquire certain international legal obligations.Footnote 31 The very concept of a unilateral act implies that a State may, through its own will manifested publicly, undertake to abide by a course of conduct or otherwise oblige itself legally.Footnote 32 A unilateral act is so described because it generates legal effects unilaterally, as opposed to international agreements and treaties where obligations are created by consensus, ie through the ‘meeting of minds’.Footnote 33
The view that reservations are essentially ‘unilateral’ is not completely novel, although the understanding of ‘unilaterality’ has dramatically changed. Prior to the Vienna Convention, socialist States held the theory that a reservation would modify treaty relations regardless of the acceptance of other State parties.Footnote 34 This is because the making of a reservation is an exercise of State sovereignty, which should not in any event be undermined.Footnote 35 A reservation was thus considered a unilateral act in the sense that it is an act conducted unilaterally and was capable of generating legal effects—even though the emphasis was not placed on the sovereign capacity to acquire legal obligations, but rather the capacity to exclude them. This view, however, was soon marginalized because it was felt that the consent of the addressee States were not properly taken into account. The principle of unanimity was then favoured; according to this principle a reservation is often perceived as forming part of a negotiated international agreement because the consent of the existing State parties is always required.Footnote 36
Nevertheless, the Vienna Convention embraces neither conception. Under the Vienna Convention, States have the right to formulate and withdraw reservations, although consent is still required for reservations to take effect.Footnote 37 Thus, the operation of reservations embodies both unilateral and bilateral elements: ‘they are made unilaterally, are accepted or objected to unilaterally… [but] ultimately function in a reciprocal way’.Footnote 38 Therefore, even where there are multiple stages at which ‘unilaterality [would cast] its shadow’,Footnote 39 reservations are generally not considered unilateral acts under international law for it is impossible to generate legal effects unilaterally.
Nonetheless, even if reservations are not considered unilateral acts in the strict sense,Footnote 40 they resemble unilateral acts in two fundamental ways. Firstly, by necessary implication, unilateral acts embody the element of non-participation.Footnote 41 The 1997 Report of the Working Group on Unilateral Act of States remarked that:
The fundamental characteristic of unilateral legal acts is, logically, their unilateral nature. They emanate from one single side (from the Latin ‘latus’), in other words, from one or several subjects of international law acting ‘unilaterally’ and the participation of another party is not required.Footnote 42
A unilateral act is a ‘manifestation of the will of one or more States in individual, collective or concerted form, in which other States, and in particular the addressee State, do not participate’.Footnote 43 The validity of such acts is often attributed to the capacity of States to consent unilaterally to legal undertakings without creating obligations on another.Footnote 44 Similarly, reservations are unilateral in the sense that their formulations do not require the participation of the addressee.Footnote 45 They assume a unilateral character in the sense that they are only ‘proposals’. Writing in 1957, Fitzmaurice noted that:
In the strict sense, all reservations, even those which it has been agreed in advance may be made (where such is the case), are unilateral inasmuch as any particular reservation is only the act of, and privy to, the particular country making it, and only relates to its own obligations under the treaty … [T]he reservation is unilateral not only in form but in substance and at that stage, is strictly only entitled by courtesy to be called a reservation, for in principle until the reservation is admitted and accepted, expressly or sub silentio, it is only a proposal and not a completed and operative reservation.Footnote 46
In other words, reservations come into existence for all other parties at the moment of the reserving State's signature, ratification or acceptance of the treaty, and before it is operative between State parties.Footnote 47 A textual reading of the Vienna Convention supports this observation. The process of entering a reservation is elaborated in Articles 19–21 of the Vienna Convention. Article 19 addresses the circumstances when a reservation may be formulated.Footnote 48 Article 20 provides for the acceptance of or objection to a reservation by an addressee State.Footnote 49 Article 21 of the Vienna Convention addresses the effect of a reservation ‘established’ in accordance with the articles above.Footnote 50 In such a way, the Vienna Convention expressly distinguishes a reservation ‘formulated’ (Article 19) and a reservation ‘established’ (Article 21).Footnote 51 Through Article 19, the Vienna Convention preserves the concept of a sovereign right to formulate (and to withdraw) reservations.Footnote 52 Yet, it makes explicit that a reservation is ‘established’ not at the time of formulation but at the time of express or tacit acceptance, ie where there is a ‘mutuality of consent’.Footnote 53
Secondly, a ‘unilateral act’ is a legally significant act, a feature which distinguishes a unilateral act from other acts of a ‘political’ nature.Footnote 54 A unilateral act in international law typically ‘denotes the creation, modification, suspension, termination, etc., of international rights and obligations’,Footnote 55 the legal effect of which largely depends on the intention of the State.Footnote 56 In the case Legal Status of Eastern Greenland (Norway v Denmark), the Permanent Court of International Justice (PCIJ) ruled that a declaration made by the Norwegian government was capable of binding itself.Footnote 57 This position was later reaffirmed in the Nuclear Tests Case (New Zealand v France):
It is well recognized that declarations made by way of unilateral acts, concerning legal or factual situations, may have the effect of creating legal obligations … When it is the intention of the State making the declaration that it should become bound according to its terms, that intention confers on the declaration the character of a legal undertaking, the State being thenceforth legally required to follow a course of conduct consistent with the declaration.Footnote 58
Whether there is such an intention is a question of construction.Footnote 59 The standard for finding such intention is nevertheless high as international law does not easily presume restrictions on State sovereignty.Footnote 60 For a unilateral declaration to be binding, the declaration must be ‘clearly intended to have that effect, and held out … as an instrument on which others may rely and under which the declarant purports to assume such obligations’.Footnote 61 In case of doubt, a restrictive interpretation is called for such that the consent of the State is not extended.Footnote 62 In Armed Activities on the Territory of the Congo (DRC v Uganda), the ICJ held that a statement by the Justice Minister of Rwanda that the State's reservations on certain provisions of the Genocide Convention would be withdrawn ‘shortly’ was not specific enough to create legal obligations.Footnote 63
Likewise, reservations too are legally significant acts.Footnote 64 By their very nature, reservations are qualified expressions of consent to be legally bound.Footnote 65 Reservations are unilateral statements communicated to the other part(ies), with the intended consequence that legal relationships would be created upon acceptance of the reservation. Moreover, a reservation is communicated at the time of ‘signing, ratifying, accepting, approving or acceding to a treaty’,Footnote 66 ie at the same instance when the reserving State manifests its consent to be bound. In this sense, it is extremely difficult to separate a reservation from the consent that it purports to convey.Footnote 67 It was therefore argued that reservations embody a type of unilateral acts that are ‘non-autonomous’, ie unilateral acts which operate within a pre-existing legal context (such as a treaty)Footnote 68 or in which their legal effect depends on the corresponding reaction of other States. As Suy commented:
… it is possible that a formally unilateral act must encounter another act of the same quality in order to be capable to produce effects. Taken separately, the two acts have no immediate legal effect as the objective legal order merely attaches potential legal effects to the first act, this is to say only under the condition that the act encounters a corresponding act designated to complete it. As typical example of this phenomenon we can cite offer and acceptance.Footnote 69
The argument in favour of viewing reservations as non-autonomous unilateral acts is therefore that a reservation is the unilateral manifestation of a State's will that is not wholly devoid of legal effect—a reservation produces an intermediate or a ‘potential’ legal effect.Footnote 70 The intermediate legal effect of such acts is further demonstrated by the requirement that in order to cancel out its intermediate legal effect, a further act of withdrawal is required to be made.Footnote 71 The analogy of offer and acceptance is particularly revealing in the context of reservations in the sense that if the text of a treaty represents the negotiated rights and obligations that were bargained for, a reservation indicates a new offer and would subsequently require a new acceptance by the State to whom the reservation was addressed. This implies that although a reservation is made in the context of a treaty, it is an act separate from the treaty itself.
The above understanding is reflected in the Special Rapporteur Alain Pellet's Third Report to the ILC produced in 1998:
…. The unilateral nature of reservations, as forcefully stated in the first few words of the Vienna definition, is not self-evident. Mr. Brierly, for example, took an entirely contractual approach to the concept of reservations: according to the first Special Rapporteur of the Commission on the law of treaties, a reservation was indissociable from its acceptance and defined by the agreement reached on its content … This position, which has now been completely abandoned, makes the reservation part of the treaty itself and is incompatible with the legal regime of reservations provided for in the 1969 Vienna Convention, which does not make the validity of a reservation subject to its acceptance by the other parties.
Although a reservation is a unilateral act separate from the treaty, however, it is not an autonomous legal act in that, first of all, it produces its effects only in relation to the treaty to whose provisions it relates and to which its fate is entirely linked and, secondly, its effects depend on the reaction (unilateral as well) or absence of reaction by the other States or international organizations which are parties. From this point of view, it is an ‘act condition’, an element of a legal relationship that it is not sufficient in itself to create. ‘A reservation is a declaration which is external to the text of a treaty. It is unilateral at the time of its formulation; but it produces no legal effects unless it is accepted, in one way or another, by another State.’ ‘A reservation is a unilateral act at the time it is formulated, but seems to stop being one in its exercise.’Footnote 72
Although the passage might not be wholly convincing—whether a contractual approach is adopted depends largely on the design of a treaty—the passage signified a change in how reservations were approached in the works of the ILC. The change in perspective was groundbreaking, but it also left many questions unanswered. For instance, when one views reservations as unilateral acts, do the rules that were originally applicable to reservations thereby change? In particular, does the law on unilateral acts now apply instead of the law of reservations? These questions were addressed in the ILC's Guide to Practice on Reservations to Treaties.
IV. THE APPROACH OF THE ILC'S GUIDE TO PRACTICE ON RESERVATIONS TO TREATIES
A. The Definition of Reservations in the Guide to Practice
The unilateral character of reservations is subsequently stressed in the Guide to Practice and its Commentary. Guideline 1.1 of the Guide to Practice on the definition of the reservations largely retains the definitions of reservations laid down in the Vienna Convention. In particular, it defines the understanding of a reservation as a (a) unilateral statement (b) made by a State or international organization either when it expresses consent to be bound by a treaty or it makes a notification of succession to a treaty, and whereby the State or organization (c) purports to modify the legal effects of a treaty.Footnote 73 As addressed above, the idea of unilaterality is reflected in these elements in the sense that a reservation is a unilateral statement made by a subject of international law without the participation of another.Footnote 74 The making of a reservation only purports to modify the legal effects of a treaty—ie it is a proposal—with its actual effect depending on the response of the addressees.
Guidelines 1.1.1 to 1.1.6 described various types of reservations—namely: statements purporting to limit the obligations of their author; statements purporting to discharge an obligation by equivalent means; reservations relating to the territorial application of the treaty; reservations formulated when extending the territorial application of a treaty; reservations formulated jointly; and reservations formulated by virtue of clauses expressly authorizing the exclusion or the modification of certain provision of the treaty.Footnote 75 In Guidelines 1.1.1 to 1.1.4 and 1.1.6, the Special Rapporteur carefully inserted the phrase ‘unilateral statements’ to the descriptions of the varying types of reservations to highlight the fact that each of these reservations are statements unilaterally made.Footnote 76 Guideline 1.1.5. on ‘reservations formulated jointly’ is further indicative of what the ILC refers to as the ‘unilateral character’ of reservations. It provides that ‘[t]he joint formulation of a reservation by several States or international organization does not affect the unilateral character of that reservation’.Footnote 77 The ILC observes that there are situations where reservations are formulated collectively by multiple States expressing to be bound by a treaty. This occurs typically where States share ‘common or similar traditions, interests or ideologies’.Footnote 78 Guideline 1.1.5 is inserted with a view to clarify that even in situations of ‘concerted reservations’, reservations are still generally considered to have been made unilaterally and individually. This proposal is based partially on practical concerns. For example, in the event where a State wishes to withdraw a jointly formulated reservation, it is unrealistic that the State has to seek the agreement of all other parties that have formulated it.Footnote 79 Conversely, it is uncertain whether a State wishing to accept/object to the reservation would be required to accept/object to the reservation in relation to all other authoring parties. The proposal that joint reservations are made unilaterally and individually is to render the operations of the relevant rules compatible with the principle of res inter alios acta.Footnote 80
B. Two Stages to Establishing a Reservation
As demonstrated above, a way to argue that reservations are unilateral acts is to suggest that the Vienna Convention construes the formulation of a reservation by the reserving State and the response of the addressee(s) as two separate acts.Footnote 81 Support for this position could be found in Article 21 of the Vienna Convention which provides that: A reservation established with regard to another party in accordance with Articles 19, 20 and 23:
(a) Modifies for the reserving State in its relations with that other party the provisions of the treaty to which the reservation relates to the extent of the reservation; and
(b) Modifies those provisions to the same extent for that other party in its relations with the reserving State.
2. The reservation does not modify the provisions of the treaty for the other parties to the treaty inter se.
3. When a State objecting to a reservation has not opposed the entry into force of the treaty between itself and the reserving State, the provisions to which the reservation relates do not apply as between the two States to the extent of the reservation.Footnote 82
The chapeau of Article 21(1) of the Vienna Convention suggests that a reservation would entail the effects stated in sub-paragraphs (a) and (b) only if it is ‘established … in accordance with Articles 19, 20, and 23’.Footnote 83 Thus, a reservation could only entail legal effects if it is compatible with the object and purpose of the treaty as prescribed under Article 19 of the Vienna Convention. An impermissible reservation is a priori void at the time of its formulation.Footnote 84 This being the case, it is only logical to think that the legal effect of an impermissible reservation does not depend on the response of the addressee (ie questions regarding the permissibility of a reservation arise before its opposability).Footnote 85 Thus, expressed or tacit acceptances to impermissible reservations are not capable of generating their purported effects (both inter partes and inter se).Footnote 86 Equally, objections to reservations on the basis of impermissibility do not, in the absence of express provisions, necessarily render a reservation illegal: objections are ‘probative and not dispositive’.Footnote 87
The above views are reflected in the Guide to Practice which further proposes that the effects of the two unilateral actions—ie the formulation of reservation by the reserving State and the acceptance/objection by the addressee State—are to be considered separately, entailing a clear conceptual separation between the initial status of the reservation and its eventual effects upon acceptance/objection.Footnote 88 Guideline 4.5.1 proposes that impermissible reservations are void ab initio: ‘[a] reservation that does not meet the conditions of formal validity and permissibility set out in Parts 2 and 3 of the Guide to Practice is null and void, and therefore devoid of any legal effect’.Footnote 89 Consequentially, Guideline 4.5.2 provides that ‘[t]he nullity of an invalid reservation does not depend on the objection or the acceptance by a contracting State or a contracting organization’.Footnote 90 Guideline 3.3.3 similarly makes clear that ‘[a]cceptance of an impermissible reservation by a contracting State or by a contracting organization shall not affect the impermissibility of the reservation’.Footnote 91 In this sense, the effect of an acceptance (or non-objection) is limited in that it only waives the right to object,Footnote 92 thus barring the accepting State from making a claim against the reserving State in the event of a breach. A subsequent acceptance (or non-objection within the period prescribed by a treaty) does not cure the illegality of the reservation nor would an acceptance save its nullity.Footnote 93
The clear emphasis on the initial (il)legality of reservations demonstrated above suggests a more cautious approach to tacit acceptances (ie non-objections). Under the Vienna Conventions, if a State is unwilling to accept a reservation proposed, it has 12 months to negotiate the amendment or withdrawal of the reservation before either choosing to object to the reservation (to the effect that the reserved provision would not apply to both parties, generating an effect which is identical to that of an acceptance in practice)Footnote 94 or not to enter into treaty relations with the reserving State at all.Footnote 95 If the addressee State does not object in time, the reserving State is entitled to rely on the addressee's silence,Footnote 96 thereby honouring the reserving State's legitimate expectation and providing a level of certainty for the reserving State to conduct its affairs. Nevertheless, this arrangement only makes sense in cases where the treaty exchanges substantive inter-State rights and interests, and hardly makes sense for treaties of a non-reciprocal nature,Footnote 97 largely owing to a lack of incentives.Footnote 98 Moreover, the failure to object may also be a result of the fact that some reservations are drafted in a manner that is abstract such that their effects are difficult to ascertain in the absence of an actual situation.Footnote 99 Thus, if tacit acceptance is to be construed, in theory, as an implied consent to the permissibility of the reservation, at issue is the quality of that consent. As the Human Rights Committee (HRC) identified, where treaty obligations do not relate to reciprocal interests, ‘it is not safe to assume that a non-objecting State thinks that a particular reservation is acceptable’.Footnote 100
C. The Competence of Treaty-Monitoring Bodies
Since a reservation comes into existence prior to the acceptance of contracting parties (as noted in section B above) and thus before it is operative as between parties, the timing of a reservation a priori implies that the legality of a reservation would come into question before acceptance (express or tacit). Thus, where the permissibility of a reservation is in doubt, the effect of the reservation is a question that should be reserved for a competent judicial/quasi-judicial body where such mechanism is available and where a treaty does not indicate that contracting States are the sole assessors of compatibility.Footnote 101
In the past, the competence of treaty-monitoring bodies to scrutinize reservations has been objected to by proponents of the opposability school, largely because the Vienna Conventions is silent in this aspect. Nevertheless, international jurisprudence dating back to the PCIJ seems clear to the extent that ‘as a general rule, any body possessing jurisdictional power has the right in the first place to itself determine the extent of its jurisdiction’.Footnote 102 In the Nottebohm Case (Preliminary Objection) (1953), the ICJ remarked that:
Since the Alabama case, it has been generally recognized that following the earlier precedents, that, in the absence of any agreement to the contrary, an international tribunal has the right to decide as to its own jurisdiction and has the power to interpret for this purpose the instruments which govern that jurisdiction.Footnote 103
In this context, it seems reasonably clear that ascertaining the permissibility and applicability of a reservation is also integral to the competence that is endowed by treaties establishing human rights monitoring bodies. Similar logic transpired in HRC's General Comment No 24:
It necessarily falls to the Committee to determine whether a specific reservation is compatible with the object and purpose of the Covenant. This is in part because … it is a task that the Committee cannot avoid in the performance of its functions. In order to know the scope of its duty to examine a State's compliance under article 40 or a communication under the first Optional Protocol, the Committee has necessarily to take a view on the compatibility of a reservation with the object and purpose of the Covenant and with general international law.Footnote 104
Yet, what remained at doubt, as Baratta observed, is the difference between the competence to ascertain the legality of a reservation and the competence to pronounce on the effects of such reservations.Footnote 105 In other words, the creation of treaty-bodies does not render treaty-bodies ‘supranational’.Footnote 106
The ILC takes a clear position supporting the competence of these bodies to assess reservations, but it also makes clear that views of the treaty-bodies are non-legally binding. Guideline 3.2 provides that contracting States or organizations, dispute settlement bodies, and treaty monitoring bodies have the competence to assess the permissibility of reservations.Footnote 107 Guideline 3.2.5 further provides that where a dispute settlement body is competent to decide upon the permissibility of the reservation, such determination is binding on parties. This is to be contrasted with Guidelines 3.2.1 and 3.2.3; the former provides that a treaty-monitoring body has the competence to assess permissibility, and the latter provides that States ‘shall give consideration to [the treaty monitoring body's] assessment of the permissibility’ (emphasis added).Footnote 108 The position of the ILC is in line with prevailing case lawFootnote 109 and views of treaty bodies.Footnote 110
D. The Emphasis on Intention and Implications for Severability
Although an impermissible reservation may be void ab initio and thus, according to Guideline 4.5.1, ‘devoid of any legal effect’, an impermissible reservation may still be legally significant as far as the consent of the reserving State is concerned. A very relevant question is whether a State's consent to be legally bound by a treaty is vitiated when a reservation is subsequently found to be impermissible.
When reservations are understood in light of their unilateral character, it becomes reasonably clear that what determines severability is the intention of the reserving State. As analogy, we may refer to judicial interpretations on reservations to declarations of acceptances to the compulsory jurisdiction of the ICJ pursuant to Article 36 of the ICJ Statute. Conventionally, rules applicable to reservations to declarations of acceptances may not be transposable to reservations to treaties because, unlike treaties, a declaration of acceptance is a unilateral act stricto sensu.Footnote 111 Declarations of acceptances ‘are facultative, unilateral engagements that States are absolutely free to make or not to make … [and are] equally free either to do so unconditionally and without limit of time for its duration, or to qualify it with conditions or reservations’.Footnote 112 Rules may only apply analogously to the extent that they are compatible with the character of these instruments.Footnote 113 Yet, if one stresses the unilateral element of reservations to treaties, especially when one makes the distinction between a reservation in its initial phase (as a proposal) with a reservation later ‘established’ upon its acceptance,Footnote 114 the unilateral proposal acquires a nature very similar to that of a reservation attached to a unilateral declaration: they are both unilateral manifestations of will and the formulation of which other States do not participate.Footnote 115
In the Case of Certain Norwegian Loans, at issue was whether Norway was entitled to rely on France's reservation on the declaration of acceptance of the Court's jurisdiction.Footnote 116 Sir Hersch Lauterpacht in his Separate Opinions decided that the French reservation was invalid; yet, rather than severing the invalid reservation from the Declaration, he came to the conclusion that the invalid reservation rendered the acceptance of the Court's jurisdiction invalid ab initio. He reasoned that:
… it is not open to the Court in the present case to sever the invalid condition from the Acceptance as a whole. For the principle of severance applies only to provisions and conditions which are not of the essence of the undertaking. Now an examination of the history of this particular form of the reservation of national jurisdiction shows that the unilateral right of determining whether the dispute is essentially within domestic jurisdiction has been regarded by the declaring State as one of the crucial limitations – perhaps the crucial limitation – of the obligation undertaken by the acceptance of the Optional Clause of Article 36 of the Statute.Footnote 117
In other words, the crucial factor is whether, from the declaring State's point of view, the reservation is an essential one—one that constitutes a condition sine qua non.
Lauterpacht further clarified his position in the Interhandel Case (Switzerland v US), which concerned a reservation to the Declaration of Acceptance by the US framed in identical wordings to the French Government's declaration in the Norwegian Loans Case:
[A] condition which, having regard to the intention of the party making it, is essential to and goes to the root of the main obligation cannot be separated from it … A party cannot be held to be bound by an obligation divested of a condition without which that obligation would never have been undertaken … . If that reservation is an essential condition of Acceptance in the sense that without it the declaring State would have been wholly unwilling to undertake the principal obligation, then it is not open to the Court to disregard that reservation and at the same time to hold the accepting State bound by the Declaration.Footnote 118
The view that a reservation incompatible with the object and purpose of a treaty may be relied upon to escape the binding effects of a treaty was in the past contested by commentators who saw no reason why a reserving State should benefit from an impermissible reservation ex injuria non oritur ius.Footnote 119 Nevertheless, in order for the maxim to apply, it would seem that a level of mala fides is required to be presumed,Footnote 120 a motive that is almost impossible to determine.Footnote 121
Subsequent case law and views that argued strongly in favour of severability reasoned instead that severability should only be a presumption. These contentions—including, most notably, the series of European Court of Human Rights (ECtHR) cases that formed the basis of the ‘Strasbourg approach’ as well as Human Rights Committee's General Comment No 24 —did not go so far as to disregard the intention of the reserving State.Footnote 122 Instead, the presumption of severability is based on the apparent contradiction that a State expressing itself to be bound by a treaty would defeat its own consent by entering a reservation that is impermissible (ie a reservation is presumed to have been made in good faith),Footnote 123 or that the reserving State, fully knowing the potential consequences of impermissible reservations, ran the risk of nevertheless formulating a broad reservation that might defeat the object and purpose of the treaty (thus implicitly consenting to be bound without the benefit of the reservation should it be found impermissible).Footnote 124
In Belilos v Switzerland, upon ruling that the Swiss ‘interpretative declaration’ amounted to a reservation that is invalid, the ECtHR decided that ‘it is beyond doubt that Switzerland is, and regards itself as, bounded by the Convention irrespective of the validity of the declaration’ (emphasis added).Footnote 125 This approach was followed in Weber v Switzerland. Footnote 126 In Loizdou v Turkey, the ECtHR noted that despite earlier case law which ruled that reservations on the relevant articles may be severed, Turkey went on to file declarations in respect of the same articles. This ‘indicates a willingness on [the State's] part to run the risk’ that such declarations, which are in fact reservations, may be severed.Footnote 127
The HRC's General Comment No 24 is often regarded as having made one of the most progressive statements in favour of severability.Footnote 128 It noted that:
The normal consequence of an unacceptable reservation is not that the Covenant will not be in effect at all for a reserving party. Rather, such a reservation will generally be severable, in the sense that the Covenant will be operative for the reserving party without benefit of the reservation.Footnote 129
Nevertheless, the position that severance is to be considered the ‘normal consequence’ was later clarified in Rawle Kennedy v Trinidad and Tobago:
Suffice it to say that even in dealing with reservations to the Covenant itself the Committee did not take the view that in every case an unacceptable reservation will fall aside, leaving the reserving state to become a party to the Covenant without benefit of the reservation. As can be seen from the section of General Comment no. 24 … the Committee merely stated that this would normally be the case. The normal assumption will be that the ratification or accession is not dependent on the acceptability of the reservation and that the unacceptability of the reservation will not vitiate the reserving state's agreement to be a party to the Covenant. However, this assumption cannot apply when it is abundantly clear that the reserving state's agreement to becoming a party to the Covenant is dependent on the acceptability of the reservation. The same applies with reservations to the Optional Protocol.Footnote 130
In other words, severance as a ‘normal consequence’ is only a presumption, which could be rebutted upon showing that the State did not, at the time of expressing to be bound, intend to become party without the benefit of the reservation.
The above line of reasoning, therefore, indicated that the effect of an impermissible reservation depends primarily on the intention of the reserving State. Guideline 4.5.3 incorporates the above ideas:
1.) The status of the author of an invalid reservation in relation to a treaty depends on the intention expressed by the reserving State or international organization on whether it intends to be bound by the treaty without the benefit of the reservation or whether it considers that it is not bound by the treaty.
2.) Unless the author of the invalid reservation has expressed a contrary intention or such an intention is otherwise established, it is considered a contracting State or a contracting organization without the benefit of the reservation.
3.) Notwithstanding paragraphs 1 and 2, the author of the invalid reservation may express at any time its intention not to be bound by the treaty without the benefit of the reservation.
4.) If a treaty monitoring body expresses the view that a reservation is invalid and the reserving State or international organization intends not to be bound by the treaty without the benefit of the reservation, it should express its intention to that effect within a period of twelve months from the date at which the treaty monitoring body made its assessment.Footnote 131
As can be seen, while sub-paragraph 1 lays down the determining factor for assessing severability (ie intention of the reserving State), sub-paragraph 2 establishes a presumption of severability. Meanwhile, sub-paragraph 4 is clearly recommendatory in nature,Footnote 132 and could not easily be reconciled with earlier case law and other Guidelines which propose that the consent of a State to be bound without the benefit of the reservation is to be ascertained at the time of consent.Footnote 133 The recommendatory nature of the sub-paragraph is also reflected in the inherently vague words ‘it should express its intention’. Nevertheless, sub-paragraph 4 only applies to treaty monitoring bodies, the decisions and concluding observations of which are generally considered non-legally binding; as noted above, decisions of dispute settlement bodies on permissibility would have had a binding effect on the reserving State. Prima facie, the proposal in sub-paragraph 4 intends to strike a balance between reserving States’ continuing participation of (predominantly) human rights treaties (ie to avoid denunciation), and at the same time avoid the consequence where a State is able to rely on an incompatible reservation as if the reservation were valid, which may result in undermining the integrity of the treaty. It is contended that sub-paragraph 4 is a more nuanced approach to the current state of affairs. Even where external aides are available in interpreting reservations (as shall be explained below), ascertaining the intention of a State is not always an easy task.Footnote 134 Moreover, this approach avoided thwarting existing constructive dialogues between treaty bodies and reserving States in persuading the latter to withdraw impermissible reservations.Footnote 135
From a broader perspective, the overall approach of the ILC on the issue of severability has far-reaching implications to the practice of reservations. First, the approach promotes greater responsibility and readjusts the imbalance that is conventionally thought to favour the reserving State.Footnote 136 It has been argued that the conventional Vienna regime ‘give[s] an unacceptable advantage to a reserving state’Footnote 137 in the sense that the reserving State may formulate wide reservations without consequences: ie when a reservation is incompatible with the object and purpose of a treaty, the State cannot be bound by the treaty without the benefit of the reservation since it cannot be bound by obligations without its consent; and when the reservation is compatible with the object and purpose of the treaty, the reservation will operate with intended effects ‘to the extent of the reservation’ whether it is accepted or objected.
The presumption of severability alters that imbalance and heightens the stakes for the reserving State. Where a reserving State has the genuine intention to become party to a treaty, the onus now falls squarely on that State to ensure that its reservations are compatible. The reserving State may not be able to rely on the uncertainty that pertains to the relevant rules under the Vienna Conventions, according to which the addressee's silence within 12 months may be deemed acceptance of the reservations’ validity. This approach would also promote a more cautious attitude towards reservations drafting and encourages reservations that are less vague and less aggressive.
Second, the approach promotes predictability in several ways. For instance, the effects of reservations are more readily ascertainable when reserving States are less inclined to formulate vague reservations. Moreover, from the perspective of the reserving party, the consequence of invalid reservations is rendered more predictable, as the reserving party is encouraged to make its intention known. In such a way, the approach provided by the Guide to Practice also better preserves the consent of both parties. Where the scope and effect of reservations are more predictable, the addressee State is in a better position to assess whether to accept or object a reservation. In this context, it is safer to assume that a non-objection should mean tacit acceptance. For the reserving State, the fact that it would be required to give more thought before entering into treaty relations arguably improves the quality of consent and would arguably increase its willingness to comply with the terms of the treaty. Consent is also better preserved as the reserving State knows ex ante the potential consequences of impermissibility.Footnote 138
Third, this approach brings greater coherence to the law on reservations. In particular, it narrows the gap that was thought to exist between ‘contract treaties’ and those treaties that cannot, strictly speaking, be reduced to pairs of bilateral relations. A typical example of the latter includes human rights treaties. Since obligations pertaining to human rights treaties are articulated for the benefit of individuals in the contracting State and in most cases do not translate into substantial rights and benefits for other State parties,Footnote 139 there is consequently little incentive for States to scrutinize reservations,Footnote 140 and objections to reservations remain scarce.Footnote 141 The Guide to Practice introduces crucial safeguards in this respect by first arguing that reservations are partly unilateral acts, then affirming the competence of monitoring bodies in scrutinizing reservations, and subsequently introducing the presumption of severability. Moreover, it achieves the above by providing a solid doctrinal basis for these positions without having to establish a ‘special regime’ for human rights treaties.Footnote 142
Thus, the arrangement under the Guide to Practice has the potential to lead to a more coherent theory and practice on reservations while striking a delicate balance between the need to take into account the consent of both the reserving and the non-reserving States, especially in contexts of normative or human rights treaties, where ‘[t]he usefulness of objections … has been repeatedly questioned’.Footnote 143
E. Unilaterality and the Interpretation of Reservations
Interpretations of reservations occur in multiple stages of adjudication: to determine whether a unilateral statement should be construed as a interpretative declaration or a reservation; to determine the compatibility of the reservation to the object and purpose of the treaty; to ascertain the exact scope of the reservation and its effects; and to determine the effect/consequences of a reservation where the reservation is invalid. Given the importance of interpreting reservations, rules in this respect are surprisingly unclear. If reservations are to be construed as (non-autonomous) unilateral acts, the question ought to be asked whether rules concerning the interpretation of treaties or rules concerning the interpretation of unilateral acts should apply in interpreting reservations.
A major difference between the law of treaties and the law of unilateral acts concern their interpretation, which naturally arises as a result of the fact that treaty provisions are negotiated texts and unilateral statements are not. The aim of interpreting treaty provisions is, in principle,Footnote 144 to give effect to the common intention of the parties as to the rights and obligations agreed in the negotiated text.Footnote 145 For instance, in Land and Maritime Boundary between Cameroon and Nigeria, the ICJ pronounced that a treaty provision must be interpreted in accordance ‘with the intention of the parties at the time’.Footnote 146
When it comes to the interpretation of a unilateral statement, emphasis is placed on the intention of the author State. The emphasis on the author's intention was stressed in the Anglo-Iranian Oil Co (Preliminary Objections), whereby the Court acknowledged the particular way in which Iran's declaration was phrased as ‘a decisive confirmation of the intention of the Government of Iran at the time when it accepted the compulsory jurisdiction of the Court’.Footnote 147 This approach was followed in the Fisheries Jurisdiction (Spain v Canada) Jurisdiction of the Court, in which the ICJ placed emphasis on the intention of the reserving State as one of the main criteria for interpreting the reservation attached to a declaration on the jurisdiction of the court: ‘… since a declaration under article 36, paragraph 2, of the Statute is a unilaterally drafted instrument, the Court has not hesitated to place a certain emphasis on the intention of the depositing State’.Footnote 148 The emphasis on the intention of the author, although it may be criticized for its apparent disregard for the expectations and reliance of the addressees, is consistent with the principle that restrictions on State sovereignty should not be implied lightly.Footnote 149
Nevertheless, like interpretations of treaty provisions, the text of the statement remains the main reliable source upon which intention is construed. In The Legal Status of Eastern Greenland, the PCIJ sought to determine the legal effects of a declaration upon ‘a careful examination of the words used’.Footnote 150 In other words, what remained relevant was the manifest intention of the reserving State at the time when the reservation was formulated. The same is provided in existing case law on the interpretation of treaty reservations. In Boyce et al. v Barbados before the Inter-American Court of Human Rights (IAmCHR), the IAmCHR was confronted with the question whether a reservation submitted by Barbados at the time it ratified the Inter-American Convention on Human Rights prevented the Court from deciding issues concerning capital punishments. The Court made it clear that ‘in interpreting reservations[,] the Court must first and foremost rely on a strictly textual analysis’.Footnote 151 In the Restrictions on Death Penalty advisory opinion, the IAmCHR remarked that, ‘without excluding the possibility that supplementary means of interpretation might, in exceptional circumstances, be resorted to, the interpretation of reservations must be guided by the primacy of the text’.Footnote 152 In other words, intention is inferred from the ‘objective or objectively verifiable factors, such as the content of the statement and its communication to the addressees, in terms of the literal meaning of the words used’.Footnote 153
Unlike treaty interpretation, however, evidence admissible to support the interpretation of unilateral statements is arguably more relaxed, and includes, for instance, materials that would shed light on the circumstances pertaining the reserving State when the reservation was made,Footnote 154 including the travaux préparatoires of the ratification process,Footnote 155 as well as internal sources regarding the preparation of the reservation,Footnote 156 such as the relevant legislative proposals, press communiqué, parliamentary debate, and ministerial statements.Footnote 157 Thus, in Anglo-Iranian Oil Co., the ICJ acknowledged that an Iranian law approving the declaration to accept the compulsory jurisdiction of the Court was relevant to ascertaining the intention of the Iranian government at the time it ratified the declaration.Footnote 158 Interestingly, case law seems to support the same approach to be applied to reservations to treaties. In Weber v Switzerland, the ECtHR decided that ‘[t]he concepts in a reservation should be understood with reference to the domestic law of the State which made it’.Footnote 159 Moreover, in interpreting a reservation, intention of the author ought to be ascertained at the time of expression of consent not after.Footnote 160 This view is in line with earlier ICJ jurisprudence in the Fisheries Jurisdiction (Spain v Canada), when the Court was tasked to interpret a reservation attached to a declaration of the Court's jurisdiction. It held: ‘The Court will thus interpret the relevant words of a declaration including a reservation contained therein in a natural and reasonable way, having due regard to the intention of the State concerned at the time when it accepted the compulsory jurisdiction of the Court.Footnote 161
The Guide to Practice and Commentary acknowledged the fact that the unilateral character of reservations has had an effect on how reservations ought to be interpreted. In its Commentary to Guideline 4.2.6 on the interpretation of reservations, the ILC explained:
Since reservations are unilateral acts, the Commission based itself on the guidelines for interpreting such acts contained in the Guiding Principles applicable to unilateral declarations of States capable of creating legal obligations, which it adopted in 2006. It should not be forgotten, however, that reservations are acts attached to a treaty, the legal effect of which they purport to modify or exclude. Consequently, the treaty is the context that should be taken into account for the purposes of interpreting the reservation.Footnote 162
Guideline 4.2.6 of the Guide to Practice therefore provided that:
A reservation is to be interpreted in good faith, taking into account the intention of its author as reflected primarily in the text of the reservation, as well as the object and purpose of the treaty and the circumstances in which the reservation was formulated.Footnote 163
Two aspects of Guideline 4.2.6 are worthy of attention. First, as noted above, where reservations are viewed as unilateral acts, the exercise of interpreting reservations seek to honour the intention of the author, placing due emphasis on the text of the reservation.Footnote 164 Moreover, Guideline 4.2.6 is correct to refer to circumstances surrounding the formulation of a reservation as references to ascertaining intention—an indication that the issue of intention is a question of fact not a question of law.Footnote 165 In Rawle Kennedy v Trinidad, the HRC concluded that the State party's denunciation of, and immediate re-accession to, the Optional Protocol subsequent to the HRC's earlier pronouncement on the severability of a reservation was a strong indication that the State party did not intend to be bound by the treaty without the benefit of the reservation:
In these particular circumstances it is quite clear that Trinidad and Tobago was not prepared to be a party to the Optional Protocol without the particular reservation, and that its re-accession was dependent on [the] acceptability of that reservation. It follows that if we had accepted the Committee's view that the reservation is invalid we would have had to hold that Trinidad and Tobago is not a party to the Optional Protocol.Footnote 166
The second aspect worthy of attention is its reference to the object and purpose of the treaty. Unlike other unilateral acts, reservations are necessarily statements that arise in the context of a treaty. Therefore, rules concerning the interpretation of reservations have to be adapted to the sui generis character of an expression to be bound by a treaty.Footnote 167 Commentary on Guideline 4.2.6 explains that ‘[t]he exogenous elements to consider in the interpretation of the reservation should include the object and purpose of the treaty, since the reservation is a non-autonomous unilateral act, which only produces an effect within the framework of the treaty’.Footnote 168 Indeed, the reference to the object and purpose to the treaty is particularly relevant. For instance, when the reserving State formulates a reservation, it is presumed that the State did not intend to defeat its intention to ratify the treaty by drafting a reservation that is incompatible with the object and purpose of the treaty. This reasoning was reflected in the Restrictions on Death Penalty advisory opinion:
In interpreting reservations, account must be taken of the object and purpose of the relevant treaty which, in the case of the Convention, involves the ‘protection of the basic rights of individual human beings, irrespective of their nationality, both against the State of their nationality and all other contracting States’. (reference omitted) The purpose of the Convention imposes real limits on the effect that reservations attached to it can have. If reservations to the Convention, to be permissible, must be compatible with the object and purpose of the treaty, it follows that these reservations will have to be interpreted in a manner that is most consistent with that object and purpose.Footnote 169 (Emphasis added.)
However, this approach is not unproblematic, especially in the context of human rights treaties. One of the rationales behind the strong emphasis placed on the intention of the reserving State is the principle that unilateral declarations and acts are generally to be interpreted in a manner consistent with the intention of the reserving State.Footnote 170 Nevertheless, human rights monitoring bodies often take a different approach, arguing that inasmuch as the object and purpose of human rights treaties is to secure for individuals the rights provided under these treaties, ambiguities arising from any restrictions on these rights should be interpreted in the interest of rights-holders. Thus, in the Effect of Reservations on the Entry into Force of the American Convention on Human Rights Advisory Opinion, the IAmCHR reasoned:
[M]odern human rights treaties in general, and the American Convention in particular are not multilateral treaties of the traditional type concluded to accomplish reciprocal exchange of rights for mutual benefit of the contracting States. Their object and purpose is the protection of the basic rights of individual human beings, irrespective of their nationality, both against the State of their nationality and all other contracting States. In concluding these human rights treaties, the States can be deemed to submit themselves to a legal order within which they, for the common good, assume various obligations, not in relation to other States, but towards all individuals within their jurisdiction.Footnote 171 (Emphasis added.)
The precise effect of the above is uncertain and the question may reasonably be asked whether, when faced with two possible interpretations, preference will be afforded to the interpretation that maximizes the protection afforded to individuals rather than the one that best reflects the intention of the reserving State, ie whether ambiguities in reservations would be resolved contra proferentem. Footnote 172 The Guide to Practice and Commentary acknowledges the potential inconsistency without providing an affirmative answer.Footnote 173
V. CONCLUSIONS: TOWARDS A ‘HYBRID’ APPROACH TO RESERVATIONS
To conclude, the approach taken by the ILC to construe reservations as non-autonomous unilateral acts has far-reaching implications. Once a reservation is taken as a (non-autonomous) unilateral act, certain aspects of reservations are to be governed by the laws applicable to unilateral acts. Moreover, since a unilateral act is an expression of consent, the intention of the State plays a significant role in determining the scope of consent that the reserving State has given when the reservation was made. Therefore, the intention of the reserving State becomes particularly relevant in interpreting the scope of the reservation as well as the consequences of impermissibility. In this respect, the Guide to Practice envisaged a ‘hybrid’ approach where the laws of unilateral acts and the law of treaties overlap in the context of reservations. While the former is relevant when consent is at issue, the latter continues to apply to formal procedures, including the withdrawal, suspension and termination of reservations. Most interestingly, such a construction provided plausible answers to a series of highly complex questions:
1. Since reservations are unilateral acts, the permissibility of a reservation depends entirely on its compatibility with the object and purpose of the treaty (unless it is expressly or impliedly provided otherwise). Acceptances and objections by States may be useful in assessing the compatibility of reservations, yet they are not conclusive. Imagining reservations as unilateral acts entails that the permissibility of a reservation can be objectively determined by a dispute settlement mechanism.
2. An impermissible reservation is void ab initio, ie void at the time it was formulated. Subsequent acceptances and non-objections will not render an otherwise illegal unilateral act lawful.
3. When an interpretation of reservation is involved, the emphasis is placed on the intention of the reserving State as to the scope and content of the reservation.
4. The consequence of an impermissible reservation also depends on the intention of the reserving State at the time when the reservation was made. This includes whether the reserving State intended to be bound by the treaty without the benefit of the reservation if a reservation is subsequently found impermissible. Severability is presumed on the assumption that the reserving State did not intend to frustrate its own accession to the treaty in the first place by submitting a reservation that would defeat the treaty's object and purpose.
It remains to be seen whether States and international judicial/quasi-judicial bodies will endorse ILC's novel approach to reservations. Yet, while not legally binding, the Guide to Practice is bound to be impactful and will certainly provide lawyers with guidance in their future practice. For academics, it will continue to be a valuable source for reflection.
