Related Rule
Belgium
Practice Relating to Rule 137. Participation of Child Soldiers in Hostilities
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 … :
7. … using [children under the age of 15] to participate actively in hostilities. 
Belgium, Penal Code, 1867, as amended on 5 August 2003, Chapter III, Title I bis, Article 136 quater, § 1(7).
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 bis. … using [children under the age of 15] to participate actively in hostilities. 
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 bis).
At the 27th International Conference of the Red Cross and Red Crescent in 1999, Belgium pledged “to prohibit in times of war any person under 18 to take part in any kind of armed operational engagement”. 
Belgium, Pledge made at the 27th International Conference of the Red Cross and Red Crescent, Geneva, 31 October–6 November 1999.
In 2002, upon ratification of the 2000 Optional Protocol on the Involvement of Children in Armed Conflict, Belgium declared:
The Government of the Kingdom of Belgium states that it is absolutely forbidden under Belgian law for any person under the age of 18 years to participate in times of war and in times of peace in any peacekeeping operation or in any kind of armed operational engagement. 
Belgium, Declaration made upon ratification of the 2000 Optional Protocol on the Involvement of Children in Armed Conflict, 6 May 2002.
In 2004, in its initial report to the Committee on the Rights of the Child under the 2000 Optional Protocol on the Involvement of Children in Armed Conflict, Belgium stated:
Belgian law complies with the obligation of States to take all practical measures to ensure that members of their armed forces who have not attained the age of 18 years do not take a direct part in hostilities, whether in peacekeeping operations or in armed operational engagement.
Belgium prohibits the participation of persons under 18 in peacekeeping operations. This results from a combination of several provisions:
(a) Articles 9 and 10 of the Act of 20 May 1994 concerning the operational deployment of the armed forces, their physical preparation and the periods and positions in which soldiers may find themselves (Moniteur belge, 21 June 1994);
(b) Articles 28, 35 and 38 of the Royal Decree of 11 August 1994 concerning the training of military candidates on the active list (Moniteur belge, 24 August 1994); and
(c) Article 1 of the Royal Decree of 6 July 1994 concerning the determination of operational forms of engagement and preparatory activities for the operational deployment of the armed forces (Moniteur belge, 20 July 1994).
The Act of 22 March 2001 amending certain provisions concerning the statutes for military personnel (Moniteur belge, 7 April 2001) introduced an article 3 bis into the aforementioned Act of 20 May 1994 prohibiting the participation in time of war of military candidates under 18 years of age in any type of operational armed engagement. This new provision supplements the existing system and reinforces the protection of military candidates under 18.
No individual under 18 years of age serving in the armed forces has … participated directly in military activities during hostilities outside Belgium. 
Belgium, Initial report to the Committee on the Rights of the Child under the Optional Protocol on the Involvement of Children in Armed Conflict, 15 August 2005, UN Doc. CRC/C/OPAC/BEL/1, submitted 30 March 2004, §§ 7–10.
Belgium further stated:
Article 3 bis introduced into the Act of 20 May 1994 by the Act of 22 March 2001 (Moniteur belge, 7 April 2001) … prohibits a military candidate under 18 years of age who is in training in time of war from participating in any type of armed operational engagement.
It is thus clear that, despite this apparent exception to the rule of the required minimum age of 18, any form of direct or indirect participation by Belgian soldiers under 18 years of age in armed conflict is prohibited. 
Belgium, Initial report to the Committee on the Rights of the Child under the Optional Protocol on the Involvement of Children in Armed Conflict, 15 August 2005, UN Doc. CRC/C/OPAC/BEL/1, submitted 30 March 2004, §§ 27–28.
Belgium also stated:
The armed forces conduct internal checks to ensure that military personnel under 18 years of age are not serving outside the national territory. This situation does not arise in practice, since military personnel in this age group are still in training and are not permitted to be in intensive service, assistance (except on national territory) or involved in operational engagement. 
Belgium, Initial report to the Committee on the Rights of the Child under the Optional Protocol on the Involvement of Children in Armed Conflict, 15 August 2005, UN Doc. CRC/C/OPAC/BEL/1, submitted 30 March 2004, § 58.
In 2006, in its written replies to the questions raised by the Committee on the Rights of the Child with regard to Belgium’s initial report under the 2000 Optional Protocol on the Involvement of Children in Armed Conflict, Belgium stated:
As regards … making [children under the age of 15] take an active part in hostilities, article 8 of the Act of 5 August 2003 [on serious violations of international humanitarian law] … introduces a new provision into the Belgian Criminal Code (art. 136 quater, para. 1, point 7) under which such acts can be prosecuted as war crimes. 
Belgium, Written replies to the list of issues to be taken up in connection with the consideration of the initial report of Belgium to the Committee on the Rights of the Child under the Optional Protocol on the Involvement of Children in Armed Conflict, 3 April 2006, UN Doc. CRC/C/OPAC/BEL/Q/1/Add.1, submitted 30 March 2006, p. 2.
In 2007, during a debate in the UN Security Council on peace and security in Africa, the Prime Minister of Belgium stated:
… each one of [the many thousands of tragic, shocking tales of child soldiers on the African continent today] is a stain on the soul of human civilization – an unacceptable stain that politicians cannot and must not ignore. … The international community must reach an agreement on stopping development aid to countries that use child soldiers in their army.
Offending countries must not only be named, or shamed, but must actually be punished. But above all, the offenders themselves must be put on trial. Take, for example, [Joseph] Kony, the so-called leader of the Lord’s Resistance Army of Uganda. He alone has been responsible for the abuse of almost 70,000 child soldiers on the African continent. … Let us arrest him and put him on trial and make an example of him, as a warning to all criminals that the exploitation of children in armed conflicts is not possible in this modern world. 
Belgium, Statement by the Prime Minister of Belgium before the UN Security Council on “Peace and security in Africa”, 25 September 2007, p. 12.
In 2007, during the 62nd Session of the UN General Assembly, the Belgian Minister of Foreign Affairs stated: “Conflicts affect civilian population far beyond the end of hostilities. … This is … why [Belgium] carries out an action against the … use of child soldiers.” 
Belgium, Statement by the Minister of Foreign Affairs at the 62nd Session of the UN General Assembly, 1 October 2007, p. 6.