Norma relacionada
Switzerland
Practice Relating to Rule 22. The Principle of Precautions against the Effects of Attacks
Switzerland’s Basic Military Manual (1987) specifies that: “To the extent possible, that is, as far as the interests of Swiss national defence allow, … other measures of protection of the civilian population must be taken.” 
Switzerland, Lois et coutumes de la guerre (Extrait et commentaire), Règlement 51.7/II f, Armée Suisse, 1987, Article 29(3).
Switzerland’s Regulation on Legal Bases for Conduct during an Engagement (2005) states:
165 The following precautionary measures must be taken into consideration when making decisions, when issuing orders and in particular when conducting military operations.
170 Anyone who acts in defence:
3 must take all other necessary precautions to protect civilians and civilian objects against the danger of the hostilities. 
Switzerland, Bases légales du comportement à l’engagement (BCE), Règlement 51.007/IVf, Swiss Army, issued based on Article 10 of the Ordinance on the Organization of the Federal Department for Defence, Civil Protection and Sports of 7 March 2003, entry into force on 1 July 2005, §§ 165 and 170(3). The German language version notes in § 170(3): “must take other necessary [“weitere notwendige”] precautions to protect civilians and also [“auch”] civilian objects against the dangers of military operations [“Kriegshandlungen”]”.
[emphasis in original]
In 2009, in a statement before the UN Security Council during an open debate on the protection of civilians in armed conflict, the permanent representative of Switzerland stated:
The current situation in Gaza cries out to us the importance of the issue we are discussing today. The main victims of the Israeli-Palestinian conflict are civilians. Switzerland is deeply shocked by the very high number of civilians that have been killed or wounded in this conflict, and in particular the high number of child victims. …
Switzerland therefore reiterates its call for … strict compliance with international law by all parties to the conflict. This includes in particular the obligation to respect the principles of distinction, proportionality and precaution. 
Switzerland, Statement by the permanent representative of Switzerland before the UN Security Council on the protection of civilians in armed conflict, 14 January 2009, p. 5.
In 2012, Switzerland’s Federal Department of Foreign Affairs issued a press release entitled “Official visit by the Palestinian President”, which stated:
During the meeting, the Head of the FDFA [Federal Department of Foreign Affairs] expressed his deep concern at the escalation of violence throughout the region. It is crucial that all measures of precaution be taken so as to spare the civilian population from the effects of the hostilities being conducted in one of the most densely populated zones in the world. 
Switzerland, Federal Department of Foreign Affairs, “Official visit by the Palestinian President”, Press Release, 15 November 2012.
In 2013, in a statement at the Meeting of the High Contracting Parties to the 1980 Convention on Certain Conventional Weapons, the permanent representative of Switzerland stated:
The community of States cannot remain indifferent to the human suffering caused by armed conflicts. It was in direct response to this fundamental concern that the CCW [1980 Convention on Certain Conventional Weapons] and its protocols were adopted, with a view to prohibiting or limiting the use of certain specific types of weapons known to inflict superfluous injury or unnecessary suffering, or to strike indiscriminately.
In this regard, Switzerland is deeply concerned by the alleged use of weapons in Syria falling within the ambit of the CCW and its respective protocols, such as the alleged use of anti-personnel mines as well as the alleged use of incendiary weapons in populated areas causing severe human suffering. We call upon all parties to the conflict to comply with their obligations under international law, in particular the principles of distinction, precaution, and proportionality. 
Switzerland, Statement by the permanent representative of Switzerland at the Meeting of the High Contracting Parties to the Convention on Certain Conventional Weapons, 14 November 2013.
Switzerland’s Basic Military Manual (1987) specifies that precautions against the effects of attacks should be taken in order to protect civilians “to the extent possible, that is, as far as the interests of national defence allow”. 
Switzerland, Lois et coutumes de la guerre (Extrait et commentaire), Règlement 51.7/II f, Armée Suisse, 1987, Article 29(3).
The manual later states: “In case of doubt, the constraints of national defence prevail.” 
Switzerland, Lois et coutumes de la guerre (Extrait et commentaire), Règlement 51.7/II f, Armée Suisse, 1987, Article 151(3).
Upon ratification of the 1977 Additional Protocol I, Switzerland stated:
Considering that [Article 58 of the 1977 Additional Protocol I] contains the expression ‘to the maximum extent feasible’, paragraphs (a) and (b) will be applied subject to the defence requirements of the national territory. 
Switzerland, Reservations made upon ratification of the 1977 Additional Protocol I, 17 February 1982, § 2.
In 2005, Switzerland withdrew its reservations to Articles 57 and 58 of the 1977 Additional Protocol I. 
Switzerland, Withdrawal of reservations to the 1977 Additional Protocol I, 17 June 2005.