Related Rule
France
Practice Relating to Rule 84. The Protection of Civilians and Civilian Objects from the Effects of Incendiary Weapons
France’s LOAC Teaching Note (2000) states: “The use of incendiary weapons is strictly limited to military objectives.” It also states: “It is forbidden to launch an attack with incendiary weapons against military objectives located near or within a concentration of civilians.” 
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: “The use of incendiary weapons is strictly limited to military objectives.” It adds: “It is forbidden to launch an attack with incendiary weapons against military objectives located near or within a concentration of civilians.” 
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.
The manual also states:
It is possible to use incendiary weapons when the military target is clearly separated from the civilian concentration and all feasible precautions are taken with a view to limiting the incendiary effects to the military objective, when the tactical situation allows it. 
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. 24.
As regards napalm and flame-throwers, the manual repeats the same provision and quotes Article 1 of the 1980 Protocol III to the Convention on Certain Conventional Weapons. 
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, pp. 86 and 79.
Upon ratification of the 1980 Convention on Certain Conventional Weapons, France declared:
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 [I, II and III] to all armed conflicts referred to in articles 2 and 3 common to the Geneva Conventions of 12 August 1949 [international and non-international armed conflicts]. 
France, Reservations made upon ratification of the Convention on Certain Conventional Weapons, 4 March 1988.
In 1987, the French Ministry of Foreign Affairs explained that the reasons for which France refused to ratify the 1980 Protocol III to the Convention on Certain Conventional Weapons was the provision relating to the use of incendiary weapons against military objectives located within a concentration of civilians. It considered the provision to be “too imprecise, thus unrealistic”. 
France, Ministry of Foreign Affairs, Statement of 2 December 1987 by the Secretary of State before the National Assembly, excerpt reprinted in Annuaire Français de Droit International, Vol. 34, 1988, p. 900.
In 2002, upon ratification of the 1980 Protocol III to the Convention on Certain Conventional Weapons, France stated:
The French Republic accepts the provisions of article 2, paragraphs 2 and 3, insofar as the terms used in these paragraphs do not lead to the assumption that an attack using incendiary weapons launched from an aircraft would involve any greater risk of indiscriminate hits than one launched by any other means.
It is the understanding of the French Republic that the term “clearly separated” used in article 2, paragraph 3, can be interpreted as meaning either a separation in terms of space or a separation by means of a physical barrier between the military target and the concentration of civilians. 
France, Interpretative declarations made upon ratification of the 1980 Protocol III to the Convention on Certain Conventional Weapons, 18 July 2002.
In 2010, in its objection to the reservation by the United States of America to the 1980 Protocol III to the Convention on Certain Conventional Weapons, France stated:
The Government of the French Republic has examined the reservation made by the United States of America upon acceding to the … [1980] Protocol III … to the Convention on … Certain Conventional Weapons …
By this reservation, the United States of America reserves the right to use incendiary weapons against military objectives located in concentrations of civilians where it is judged that such use would cause fewer casualties and/or less collateral damage than alternative weapons.  In so doing, the reservation both excludes the prohibition set out in article 2, paragraph 2, and alters the derogation regime set out in article 2, paragraph 3.
Accordingly, the Government of the French Republic considers this reservation to be contrary to the object and purpose of the Protocol since, despite the assurances given by the United States of America, it cannot guarantee the protection of civilians, which is the raison d'être of the Protocol.  The Government of the French Republic therefore wishes to register an objection to this reservation.  This objection shall not preclude the entry into force of the Protocol between France and the United States of America. 
France, Objection to the Reservation by the United States of America to the 1980 Protocol III to the Convention on Certain Conventional Weapons, 2 February 2010.