Related Rule
Belgium
Practice Relating to Rule 154. Obedience to Superior Orders
Belgium’s Disciplinary Regulations (1991) provides: “Soldiers must loyally execute … orders given by their superiors in the interest of the service”. 
Belgium, Règlement de Discipline pour l’Armée, Etat-Major Général, Division Personnel, 18 November 1991, § 304(a); see also § 403(d).
However, the Regulations adds: “An order must not be executed if this execution can manifestly lead to the perpetration of a crime or an offence.” 
Belgium, Règlement de Discipline pour l’Armée, Etat-Major Général, Division Personnel, 18 November 1991, § 304(b).
Belgium’s Law on Discipline in the Armed Forces (1975) provides:
Soldiers must faithfully execute the orders given to them by their superiors in the interest of service. However, an order must not be executed if its execution could clearly result in the perpetration of a crime or an offence. 
Belgium, Law on Discipline in the Armed Forces, 1975, Article 11(2).
In the Sergeant W. case in 1966, Belgium’s Court-Martial of Brussels sentenced a sub-officer to three years’ imprisonment for the wilful killing of a civilian. The accused, who at the time of the event was chasing rebels, was serving in the Congolese army within the framework of military technical co-operation between Congo (Democratic Republic of the Congo) and Belgium. The Court held that the accused’s interpretation of the order he had received, i.e. to kill an unarmed person in his power, was manifestly unlawful; the accused therefore had a duty to disobey this order. 
Belgium, Court-Martial of Brussels, Sergeant W. case, Judgment, 18 May 1966.
In 2006, in its second periodic report to the Committee against Torture, Belgium stated:
As far as the military forces are concerned, article 11 of the Armed Forces (Disciplinary Regulations) Act of 14 January 1975 states that “An order may not however be implemented if implementation may manifestly involve the perpetration of a crime or an offence”. That principle was reaffirmed in the new regulations on internal discipline, Ed 01, 23 August 2005. 
Belgium, Second periodic report to the Committee against Torture, 14 August 2007, UN Doc. CAT/C/BEL/2, submitted 21 September 2006, § 490.