Norma relacionada
Practice Relating to Rule 14. Proportionality in Attack
Section C. Information required for judging proportionality in attack
Upon ratification of the 1977 Additional Protocol I, Spain declared with regard to Articles 51 to 58 inclusive:
It is the understanding [of the Spanish Government] that the decision made by military commanders, or others with the legal capacity to plan or execute attacks which may have repercussions on civilians or civilian objects or similar objects, shall not necessarily be based on anything more than the relevant information available at the relevant time and which it has been possible to obtain to that effect. 
Spain, Interpretative declarations made upon ratification of the 1977 Additional Protocol I, 21 April 1989, § 5.