Related Rule
Belgium
Practice Related to Rule 95. Forced Labour
Belgium’s Law of War Manual (1983) states that compelling a prisoner of war to serve in the armed forces of the enemy is a grave breach of the 1949 Geneva Conventions. 
Belgium, Droit Pénal et Disciplinaire Militaire et Droit de la Guerre, Deuxième Partie, Droit de la Guerre, Ecole Royale Militaire, par J. Maes, Chargé de cours, Avocat-général près la Cour Militaire, D/1983/1187/029, 1983, p. 55.
Belgium’s Penal Code (1867), as amended in 2003, provides:
War crimes envisaged in the 1949 [Geneva] Conventions … and in the [1977 Additional Protocols I and II] … , as well as in Article 8(2)(f) of the [1998 ICC Statute], and listed below, … constitute crimes under international law and shall be punished in accordance with the provisions of the present title … :
6. compelling a prisoner of war, a civilian protected by the [1949 Geneva] Convention [IV] on the protection of civilians in times of armed conflict, or a person protected by [1977] Additional Protocols I and II to the … 1949 Geneva Conventions to serve in the armed forces or armed groups of a hostile power or of the adverse party. 
Belgium, Penal Code, 1867, as amended on 5 August 2003, Chapter III, Title I bis, Article 136 quater, § 1(6).
Belgium’s Law concerning the Repression of Grave Breaches of the Geneva Conventions and their Additional Protocols (1993), as amended in 1999, provides that compelling a prisoner of war, a civilian person or persons protected by the 1977 Additional Protocols I and II to serve in the forces of a hostile power or adverse party constitutes a crime under international law. 
Belgium, Law concerning the Repression of Grave Breaches of the Geneva Conventions and their Additional Protocols, 1993, as amended in 1999, Article 1(3)(4).
Belgium’s Law relating to the Repression of Grave Breaches of International Humanitarian Law (1993), as amended in 2003, provides:
War crimes envisaged in the 1949 [Geneva] Conventions … and in the [1977 Additional Protocols I and II] … , as well as in Article 8(2)(f) of the [1998 ICC Statute], and listed below, … constitute crimes under international law and shall be punished in accordance with the provisions of the present title … :
4. compelling a prisoner of war, a civilian protected by the [1949 Geneva] Convention [IV] on the protection of civilians in times of armed conflict, or a person protected by [1977] Additional Protocols I and II to the … 1949 Geneva Conventions to serve in the armed forces or armed groups of a hostile power or of the adverse party. 
Belgium, Law relating to the Repression of Grave Breaches of International Humanitarian Law, 1993, as amended on 23 April 2003, Article 1 ter, § 1(4).