INTERNATIONAL LAW, Sixth edition

918 international law
be considered. 75 In the special case of a bilateral treaty, an interpretative
declaration made by one party which is accepted by the other party will
constitute an authoritative interpretation of that treaty. 76
The general rule that became established was that reservations could
only be made with the consent of all the other states involved in the process.
This was to preserve as much unity of approach as possible to ensure the
success of an international agreement and to minimise deviations from
the text of the treaty. This reflected the contractual view of the nature of a
treaty, 77 and the League of Nations supported this concept. 78 The effect of
this was that a state wishing to make a reservation had to obtain the consent
of all the other parties to the treaty. If this was not possible, that state
could either become a party to the original treaty (minus the reservation,
of course) or not become a party at all. However, this restrictive approach
to reservations was not accepted by the International Court of Justice in
the Reservations to the Genocide Convention case. 79 This was an advisory
opinion by the Court, requested by the General Assembly after some states
had made reservations to the 1948 Genocide Convention, which contained
no clause permitting such reservations, and a number of objections were
made.
The Court held that:
a state which has made and maintained a reservation which has been objectedtobyoneormorepartiestotheConventionbutnotbyothers,canbe
regardedasbeingapartytotheConventionifthereservationiscompatible
with the object and purpose of the Convention.
Compatibility, in the Court’s opinion, could be decided by states individually
since it was noted that:
if a party to the Convention objects to a reservation which it considers
incompatible with the object and purpose of the Convention, it
can . . . consider that the reserving state is not a party to the Convention. 80
75 See draft guideline 1.3.1 of the ILC Guide to Practice, Report of the ILC on its 54th Session,
2002, p. 53. Draft guideline 1.3.2 also states that the phrasing or name used provides an
indication of the purported legal effect, ibid.
76 Ibid., p. 56.
77 See Sinclair, Vienna Convention, pp. 54–5, and Ruda, ‘Reservations’, p. 112. See also Redgwell,
‘Universality or Integrity’, p. 246.
78 Report of the Committee of Experts for the Progressive Codification of International Law,
8 LNOJ, pp. 880–1 (1927).
79 ICJ Reports, 1951, p. 15; 18 ILR, p. 364. 80 ICJ Reports, 1951, pp. 29–30.