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United Kingdom of Great Britain and Northern Ireland
Practice Relating to Rule 14. Proportionality in Attack
Section B. Determination of the anticipated military advantage
The UK LOAC Manual (2004) states:
The military advantage anticipated from the attack refers to the advantage anticipated from the attack considered as a whole and not only from isolated or particular parts of the attack. The point of this is that an attack may involve a number of co-ordinated actions, some of which might cause more incidental damage than others. In assessing whether the proportionality rule has been violated, the effect of the whole attack must be considered. 
United Kingdom, The Manual of the Law of Armed Conflict, Ministry of Defence, 1 July 2004, § 5.33.5.
At the CDDH, the United Kingdom stated that in its view the expression “military advantage anticipated” was intended to refer to “the advantage anticipated from the attack considered as a whole and not only from isolated or particular parts of the attack”. 
United Kingdom, Statement at the CDDH, Official Records, Vol. VI, CDDH/SR.41, 26 May 1977, p. 164, § 120.
Upon ratification of the 1977 Additional Protocol I, the United Kingdom stated that the term “military advantage” as used in the proportionality test of Articles 51 and 57 of the Protocol was understood to refer to the advantage anticipated from the attack considered as a whole and not only from isolated or particular parts of the attack. 
United Kingdom, Reservations and declarations made upon ratification of the 1977 Additional Protocol I, 28 January 1998, § i; see also United Kingdom, Declarations made upon signature of the 1977 Additional Protocol I, 12 December 1977, § e and Declarations made upon ratification of the 1996 Amended Protocol II to the Convention on Certain Conventional Weapons, 13 February 1995.