相关规则
Nigeria
Practice Related to Rule 95. Forced Labour
Section B. Compelling persons to serve in the forces of a hostile power
Nigeria’s Soldiers’ Code of Conduct and Military Manual (1994) provide: “A belligerent is forbidden to compel 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.” 
Nigeria, Code of Conduct for Combatants, “The Soldier’s Rules”, Nigerian Army, undated, p. 4; International Humanitarian Law (IHL), Directorate of Legal Services, Nigerian Army, 1994, p. 40, § 6.
Nigeria’s Manual on the Laws of War states that compelling a prisoner of war and a protected person to serve in the forces of the hostile power is a grave breach of the 1949 Geneva Conventions and is considered a serious war crime. 
Nigeria, The Laws of War, by Lt. Col. L. Ode PSC, Nigerian Army, Lagos, undated, § 6(a) and (c).
The manual further states that “compelling a citizen to take part in war operations directed against his own state” is an illegitimate tactic. 
Nigeria, The Laws of War, by Lt. Col. L. Ode PSC, Nigerian Army, Lagos, undated, § 14(a).
Nigeria’s Geneva Conventions Act (1960) punishes any person who “whether in or outside the Federation, … whatever his nationality, commits, or aids, abets or procures any other person to commit any such grave breach of any of the [1949 Geneva] Conventions”. 
Nigeria, Geneva Conventions Act, 1960, Section 3(1).