Related Rule
France
Practice Relating to Rule 70. Weapons of a Nature to Cause Superfluous Injury or Unnecessary Suffering
France’s Disciplinary Regulations (1975), as amended, provides that it is prohibited “to use any means [of warfare] that causes unnecessary suffering and damage”. 
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) states: “It is prohibited to use … weapons … of a nature to cause unnecessary losses or excessive suffering.” 
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, § 4.
France’s LOAC Teaching Note (2000) states that, “owing to their inhumane nature or to their excessive traumatic effect”, the use of poison, chemical weapons, biological and bacteriological weapons, dum-dum bullets or other projectiles with expanding heads, anti-personnel mines, weapons that injure by non-detectable fragments, blinding laser weapons, and torpedoes without self-destruction mechanisms “is totally prohibited by the law of armed conflicts”. 
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. 6.
France’s LOAC Manual (2001) states that, “owing to their inhuman nature or to their excessive traumatic effect”, the use of poison, chemical weapons, biological and bacteriological weapons, dum-dum bullets or other projectiles with expanding heads, anti-personnel mines, weapons that injure by non-detectable fragments, blinding laser weapons, and torpedoes without self-destruction mechanisms “is totally prohibited by the law of armed conflicts”. 
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. 54; see also p. 97.
Following the adoption by consensus of Article 33 of the draft Additional Protocol I (now Article 35), France stated that it “went beyond the strict confines of humanitarian law and in fact regulated the law of war” and had “direct implications for the defence and security of States”. Therefore, it stated that it would have abstained if the article had not been adopted by consensus. 
France, Statement at the CDDH, Official Records, Vol. VI, CDDH/SR.39, 25 March 1977, p. 101, § 55.
Upon ratification of the 1980 Convention on Certain Conventional Weapons, France stated:
With reference to the scope of application defined in article 1 of the Convention on Prohibitions or Restrictions on the Use of Certain Conventional Weapons, … it will apply the provisions of the Convention and its three Protocols to all armed conflicts referred to in articles 2 and 3 common to the Geneva Conventions of 12 August 1949. 
France, Reservations made upon ratification of the Convention on Certain Conventional Weapons, 4 March 1988.
In its written statement submitted to the ICJ in the Nuclear Weapons case in 1995, France stated:
The supporters of that theory [according to which the law of armed conflicts would contain legal rules from which a prohibition of the use of nuclear weapons could be deduced] base themselves … on various rules or principles enunciated in [the 1977 Additional Protocol I], and specifically “the prohibition to employ weapons, projectiles and material and methods of warfare of a nature to cause superfluous injury or unnecessary suffering” (art. 35, para.2) …
The French Government formally rejects this reasoning … Besides the fact that it is not according to this procedure that the prohibitions concerning the use of arms are traditionally established, this method is random, and cannot in any case lead to the result aimed at by its authors.
The theory put forward supposes that it is established … that all the rules mentioned … correspond with customary principles recognized as such and … that the exact content of these principles is defined.
However, this content … has been the object, and still is the object, of doctrinal discussions.
With regard to this, the French government must again underline that the principles of international customary law applicable in armed conflict cannot be searched in [the 1977 Additional Protocol I] … If one cannot deny that certain provisions of the protocol find their inspiration in the principles of international customary law, it is obvious that others constitute a development.
The general practice in the field of the prohibition or the regulation of armament is to proceed by conventions …
Indeed, the regulation of the use of a weapon supposes precise rules which cannot be established other than by specific conventions. 
France, Written statement submitted to the ICJ, Nuclear Weapons case, 20 June 1995, pp. 40-45, §§ 28–30; see also Written statement submitted to the ICJ, Nuclear Weapons (WHO) case, June 1994, pp. 29–31, § 26.
The instructions given to the French armed forces for the conduct of Opération Mistral, simulating a military operation under the right of self-defence or a mandate of the UN Security Council, state: “It is prohibited to employ methods or weapons which are of a nature to cause unnecessary losses or excessive suffering.” 
France, Etat-major de la Force d’Action Rapide, Ordres pour l’Opération Mistral, 1995, Section 6, § 65.
According to the Report on the Practice of France, the French Minister of Foreign Affairs stated in an interview in 1999 that France considered Article 35 of the 1977 Additional Protocol I to have become customary. 
Report on the Practice of France, 1999, Chapter 3.1.