Соответствующая норма
Belgium
Practice Relating to Rule 14. Proportionality in Attack
Section B. Determination of the anticipated military advantage
Belgium’s Law of War Manual (1983) states that, when deciding whether or not to launch an attack, “the commander must consider the advantage of the attack as a whole (and not the advantages of specific or separate parts of the attack)”. 
Belgium, Droit Pénal et Disciplinaire Militaire et Droit de la Guerre, Deuxième Partie, Droit de la Guerre, Ecole Royale Militaire, par J. Maes, Chargé de cours, Avocat-général près la Cour Militaire, D/1983/1187/029, 1983, p. 29.
In an explanatory memorandum submitted to the Belgian Parliament in 1985 in the context of the ratification procedure of the 1977 Additional Protocols, the Belgian Government stated: “The military advantage must be assessed in the light of the attack considered as a whole.” 
Belgium, House of Representatives, Explanatory memorandum on a draft bill for the approval of the Additional Protocols, 1984–1985 Session, Doc. 1096-1, 9 January 1985, p. 11.
Upon ratification of the 1977 Additional Protocol I, Belgium 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. 
Belgium, Interpretative declarations made upon ratification of the 1977 Additional Protocol I, 20 May 1986, § 5.