Colombia
Practice Relating to Rule 14. Proportionality in Attack
Colombia’s Instructors’ Manual (1999) prohibits the disproportionate use of force. The manual states: “In time of war, the principle of proportionality must be observed. This principle means that the degree of force, the weapons used and the actions taken must be proportionate to the seriousness of the situation.”
Colombia’s Penal Code (2000) imposes a criminal sanction on “anyone who, during an armed conflict, carries out or orders the carrying out of … excessive attacks”.
Colombia’s Directive No. 10 (2007), whose objective is to prevent the killing of protected persons, states: “The principles of legality, distinction, necessity and proportionality must guide all military action.”
In 2006, in the Constitutional Case No. T-165/06, the First Appeals Chamber of Colombia’s Constitutional Court stated:
[W]ith regard to the conduct of hostilities, it is important to note that IHL is ruled by fundamental principles, such as the principles of distinction, limitation and proportionality. Indeed, … the principle of proportionality which, based on the fact that an armed conflict necessarily produces unwanted effects on the civilian population and civilian objects, prohibits military actions that predictably and intentionally result in deaths or wounded among the civilian population or harm to civilian property which would be excessive in relation to the concrete and direct military advantage sought.
In 2007, in the Constitutional Case No. C-291/07, the Plenary Chamber of Colombia’s Constitutional Court stated:
[The principle of proportionality] requires parties to an armed conflict to abstain from carrying out a military operation whenever it is possible to foresee that the damage expected to be caused to the civilian population or civilian property would be excessive in relation to the concrete and direct military advantage anticipated.

[footnote in original omitted]