Related Rule
Togo
Practice Relating to Rule 14. Proportionality in Attack
Togo’s Military Manual (1996) requires respect for the principle of proportionality. The manual states:
A military action is proportionate if it does not cause loss or damage to civilians which is excessive in relation to the expected overall result. This rule cannot justify unlimited destruction or attacks against civilians and civilian objects as such. 
Togo, Le Droit de la Guerre, III fascicules, Etat-major Général des Forces Armées Togolaises, Ministère de la Défense nationale, 1996, Fascicule III, p. 14; see also Fascicule II, p. 6.
The manual also states:
The principle of proportionality requires that needless suffering and damage be avoided. Pursuant to this principle, all forms of violence which are not indispensable to gain superiority over an enemy are prohibited. 
Togo, Le Droit de la Guerre, III fascicules, Etat-major Général des Forces Armées Togolaises, Ministère de la Défense nationale, 1996, Fascicule III, p. 11.