Related Rule
South Africa
Practice Related to Rule 95. Forced Labour
Section B. Compelling persons to serve in the forces of a hostile power
South Africa’s LOAC Manual (1996) states that “compelling a protected person to serve in the forces of the hostile power” is a grave breach of the 1949 Geneva Conventions. 
South Africa, Presentation on the South African Approach to International Humanitarian Law, Appendix A, Chapter 4: International Humanitarian Law (The Law of Armed Conflict), National Defence Force, 1996, § 40.
South Africa’s ICC Act (2002) reproduces the war crimes listed in the 1998 ICC Statute, including in international armed conflicts: “compelling a prisoner of war or other protected person to serve in the forces of a hostile Power” and “compelling the nationals of the hostile party to take part in the operations of war directed against their own country, even if they were in the belligerent's service before the commencement of the war”. 
South Africa, ICC Act, 2002, Schedule 1, Part 3, §§ (a)(v) and (b)(xv).
South Africa’s Implementation of the Geneva Conventions Act (2012) states: “A protected prisoner of war who is in the custody of the South African National Defence Force must be granted the protection of the [1949] Third [Geneva] Convention or the [1949] Fourth [Geneva] Convention, as the case may be.” 
South Africa, Implementation of the Geneva Conventions Act, 2012, Section 12(2).
The Act defines a “protected prisoner of war” as a “person protected by the Third Convention or a person who is protected as a prisoner of war under [the 1977 Additional] Protocol I”. 
South Africa, Implementation of the Geneva Conventions Act, 2012, Section 1.
The Act also states:
5. Breach of Conventions and penalties
(1) Any person who, whether within or outside the Republic, commits a grave breach of the [1949 Geneva] Conventions, is guilty of an offence.
(2) For the purposes of subsection (1), “a grave breach” means–
(c) a grave breach referred to in Article 130 of the Third Convention;
(d) a grave breach referred to in Article 147 of the Fourth Convention. 
South Africa, Implementation of the Geneva Conventions Act, 2012, Section 5(1)–(2)(c)–(d).