Related Rule
Argentina
Practice Relating to Rule 14. Proportionality in Attack
The Report on the Practice of Argentina states that in a case concerning armed operations against insurgents in 1985, “the National Court of Appeals referred to the principle of proportionality, which it considered to be a customary norm based on its repeated doctrinal approbation”. 
Report on the Practice of Argentina, 1997, Chapter 1.5, referring to National Court of Appeals, Military Junta Case, Judgment, 9 December 1985.