Related Rule
Belgium
Practice Relating to Rule 153. Command Responsibility for Failure to Prevent, Punish or Report War Crimes
Belgium’s Disciplinary Regulations (1991) states: “Superiors may be criminally or disciplinarily liable if they knew or should have known that a subordinate was committing or going to commit an offence and failed to take all measures to prevent, suppress or punish this offence.” 
Belgium, Règlement de Discipline pour l’Armée, Etat-Major Général, Division Personnel, 18 November 1991, § 404; see also § 402.
Belgium’s Penal Code (1867), as amended in 2003, provides:
The punishment for the following shall correspond to the punishment for the consummated offence:
5. omitting to act within the limits of one’s abilities when there is knowledge of orders given to execute such an offence or of facts inciting the execution thereof and when the commission thereof could have been prevented or ended. 
Belgium, Penal Code, 1867, as amended on 5 August 2003, Chapter III, Title I bis, Article 136 septies, § 5.
Belgium’s Law concerning the Repression of Grave Breaches of the Geneva Conventions and their Additional Protocols (1993), as amended in 1999, which applies to both international and non-international armed conflicts, provides:
The following shall be punishable by the penalty provided for completed breaches:
failure to act to the extent available to them by persons who had knowledge of the orders given to commit such a breach or of acts initiating the commission thereof and who were able to prevent or put an end to such breach. 
Belgium, Law concerning the Repression of Grave Breaches of the Geneva Conventions and their Additional Protocols, 1993, as amended in 1999, Article 4.
A Belgian manual containing directives for commanders notes that military discipline “grants respect for human rights and especially for the obligations required by the Geneva Convention”. 
Belgium, Etat-major Général, L’exercice du commandement. Directives pour un leadership moderne dans les forces armées, 1998, p. 41.