Related Rule
France
Practice Relating to Rule 50. Destruction and Seizure of Property of an Adversary
France’s Disciplinary Regulations (1975), as amended in 1982, states that, under international conventions, “any wanton destruction” is prohibited. 
France, Règlement de Discipline Générale dans les Armées, Decree No. 75-675 of 28 July 1975, replacing Decree No. 66-749, completed by Decree of 11 October 1978, implemented by Instruction No. 52000/DEF/C/5 of 10 December 1979, and modified by Decree of 12 July 1982, Ministère de la Défense, Etat-Major de l’Armée de Terre, Bureau Emploi, Article 9 bis (2).
France’s LOAC Summary Note (1992) provides: “Destructions not required by the mission … are forbidden.” 
France, Fiche de Synthèse sur les Règles Applicables dans les Conflits Armés, Note No. 432/DEF/EMA/OL.2/NP, Général de Corps d’Armée Voinot (pour l’Amiral Lanxade, Chef d’Etat-major des Armées), 1992, § 1.7.
The Summary Note adds that “extensive destruction and appropriation of property not justified by military necessities and carried out unlawfully and wantonly” are grave breaches of the law of war and war crimes. 
France, Fiche de Synthèse sur les Règles Applicables dans les Conflits Armés, Note No. 432/DEF/EMA/OL.2/NP, Général de Corps d’Armée Voinot (pour l’Amiral Lanxade, Chef d’Etat-major des Armées), 1992, § 3.4.
France’s LOAC Teaching Note (2000) provides: “Destruction not required by the mission is forbidden.” 
France, Fiche didactique relative au droit des conflits armés, Directive of the Ministry of Defence, 4 January 2000, annexed to the Directive No. 147 of the Ministry of Defence of 4 January 2000, p. 2.
The Teaching Note further states that “extensive destruction and appropriation of property not justified by military necessity and carried out unlawfully and wantonly” are grave breaches of the law of armed conflict and war crimes. 
France, Fiche didactique relative au droit des conflits armés, Directive of the Ministry of Defence, 4 January 2000, annexed to the Directive No. 147 of the Ministry of Defence of 4 January 2000, p. 7.
France’s LOAC Manual (2001) states that “extensive destruction or appropriation of property, not justified by military necessity, and carried out unlawfully and wantonly” is a war crime for which there is no statute of limitation under the 1998 ICC Statute. 
France, Manuel de droit des conflits armés, Ministère de la Défense, Direction des Affaires Juridiques, Sous-Direction du droit international humanitaire et du droit européen, Bureau du droit des conflits armés, 2001, p. 45.
In the Holstein case before a French Military Tribunal in 1947, some of the accused, members of various German units, were found guilty of war crimes for having destroyed by arson inhabited buildings. The Tribunal found that there was no necessity to set the houses on fire, as required by Article 23(g) of the 1907 Hague Regulations. The acts of arson committed were thus not justified by the laws and customs of war. 
France, Permanent Military Tribunal at Dijon, Holstein case, Judgment, 3 February 1947.