Related Rule
France
Practice Relating to Rule 14. Proportionality in Attack
France’s LOAC Teaching Note (2000) provides that the action of both commanders and combatants must be guided by respect for the fundamental principle of proportionality. 
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.
France’s LOAC Manual (2001) states that the principle of proportionality requires that no attack must be launched,
which may be expected to cause incidental loss of civilian lives, injuries to civilians, damage to civilian objects, or a combination thereof, which would be excessive in relation to the concrete and direct military advantage anticipated. The application of this principle raises the question of the balance between the means used and the desired military effect. The application of the principle of proportionality does not exclude that collateral damage may be suffered by the civilian population or civilian objects provided they are not excessive in relation to the concrete and direct military advantage anticipated. 
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. 13–14.
France’s Code of Defence (2004), as amended in 2008, states: “Combatants must refrain from any attack that may incidentally inflict damage to protected persons or objects which is excessive in relation to the military advantage anticipated.” 
France, Code of Defence, 2004, as amended in 2008, Article D4122-10.
The Code also states that “civilians … are protected persons”. 
France, Code of Defence, 2004, as amended in 2008, Article D4122-10.
France’s Penal Code (1992), as amended in 2010, states in its section on war crimes related to international armed conflict:
Intentionally launching an attack in the knowledge that it will cause incidental loss of life or injury among the civilian population which would be clearly disproportionate in relation to the concrete and direct military advantage anticipated for the overall attack is punishable by life imprisonment. 
France, Penal Code, 1992, as amended in 2010, Article 461-27.
The Penal Code also states, under the same section:
Intentionally launching an attack in the knowledge that it will cause incidental … damage to civilian objects which would be clearly disproportionate in relation to the concrete and direct military advantage anticipated for the overall attack … is punishable by 20 years’ imprisonment. 
France, Penal Code, 1992, as amended in 2010, Article 461-28.
At the CDDH, France voted against Article 46 of the draft Additional Protocol I (now Article 51) because it considered:
The provisions of paragraphs 4, 5 and 7 were of a type which by their very complexity would seriously hamper the conduct of defensive military operations against an invader and prejudice the exercise of the inherent right of legitimate defence recognized in Article 51 of the Charter of the United Nations. 
France, Statement at the CDDH, Official Records, Vol. VI, CDDH/SR.41, 26 May 1977, p. 163, § 118.
In 2009, the Minister of Foreign and European Affairs of France stated:
Violations of humanitarian law are ever increasing, as the current crises are unfortunately there to remind us, whether we are looking at Darfur, Somalia, Gaza, Sri Lanka or the Kivus. … The means and methods of warfare know no limitation or restraint, [such as] … proportionality in the use of force [and] use of the minimum violence necessary …
We must react! 
France, Minister of Foreign and European Affairs, “International Humanitarian Law, an Imperative”, La Croix, 12 February 2009, p. 1.
While the core challenges in the protection of civilians identified in the previous reports of the Secretary-General still need our sustained attention, the new report also identifies several protection policy priorities that need to be explored. In particular the following “emerging” issues would benefit from our attention, and the Group of Friends stands ready to act as a platform to advance them. …
… [O]n the issue of lethal autonomous weapons systems (LAWS), the Group is of the view that further discussions are needed and it welcomes the fact that the issue will be examined in Geneva in May 2014, in the framework of the CCW [Convention on Certain Conventional Weapons]. The Group hopes that such discussions will also examine the issue with due consideration to the protection of civilians as part of a comprehensive debate including legal, military operational, technological and ethical perspectives. In time discussion should focus on the relevance of such systems to the protection of civilians, in particular in the context of IHL and with regard to the principles of distinction, precaution and proportionality. 
France, Statement by the permanent representative of Switzerland during a UN Security Council open debate on the protection of civilians in armed conflict made on behalf of the Group of Friends on the Protection of Civilians in Armed Conflict, namely Australia, Austria, Belgium, Brazil, Canada, France, Germany, Italy, Japan, Liechtenstein, Norway, Portugal, Switzerland, the United Kingdom and Uruguay, 12 February 2014, p. 2.
Upon ratification of the 1977 Additional Protocol I, France stated that the term “military advantage” as used in the proportionality test of Articles 51 and 57 of the Protocol was understood to refer to the advantage anticipated from the attack considered as a whole and not only from isolated or particular parts of the attack. 
France, Reservations and declarations made upon ratification of the 1977 Additional Protocol I, 11 April 2001, § 10.
Upon ratification of the 1998 ICC Statute, France declared that “the term ‘military advantage’ in article 8, paragraph 2 (b) (iv), refers to the advantage anticipated from the attack as a whole and not from isolated or specific elements thereof”. 
France, Interpretative declarations made upon ratification of the 1998 ICC Statute, 9 June 2000, § 5.