Related Rule
Germany
Practice Relating to Rule 15. The Principle of Precautions in Attack
Germany’s Military Manual (1992) states: “The civilian population as such as well as individual civilians … shall be spared as far as possible.” 
Germany, Humanitarian Law in Armed Conflicts – Manual, DSK VV207320067, edited by The Federal Ministry of Defence of the Federal Republic of Germany, VR II 3, August 1992, English translation of ZDv 15/2, Humanitäres Völkerrecht in bewaffneten Konflikten – Handbuch, August 1992, § 404.
Germany’s Soldiers’ Manual (2006) states: “When attacking a military objective, all necessary precautions shall be taken to spare as far as possible the civilian population located in the area or in the immediate vicinity of the object.” 
Germany, Druckschrift Einsatz Nr. 03, Humanitäres Völkerrecht in bewaffneten Konflikten –- Grundsätze, Erarbeitet nach ZDv 15/2, Humanitäres Völkerrecht in bewaffneten Konflikten – Handbuch, DSK SF009320187, Bundesministerium der Verteidigung, R II 3, August 2006, p. 4.
Germany’s Military Manual (1992) states: “When launching an attack on a military objective, all feasible precautions shall be taken to avoiding, and in any event to minimizing, incidental losses of civilian life, injury to civilians and damage to civilian objects.” 
Germany, Humanitarian Law in Armed Conflicts – Manual, DSK VV207320067, edited by The Federal Ministry of Defence of the Federal Republic of Germany, VR II 3, August 1992, English translation of ZDv 15/2, Humanitäres Völkerrecht in bewaffneten Konflikten – Handbuch, August 1992, § 510.
In 2010, in the Fuel Tankers case, the Federal Prosecutor General at Germany’s Federal Court of Justice investigated whether war crimes or other crimes under domestic law had been committed in the course of an airstrike which was ordered by a colonel (Oberst) of the German armed forces against two tankers transporting fuel for the International Security Assistance Force in Afghanistan stolen by the Taliban near Kunduz and which resulted in the deaths of a number of civilians. The Federal Prosecutor General stated:
Pursuant to § 170 para. 2 StPO [Penal Procedure Code], the investigation proceedings which were initiated by the order of 12 March 2010 against Colonel (Oberst) Klein and Company Sergeant Major (Hauptfeldwebel) Wilhelm due to suspected offences under the VStGB [International Crimes Code] and other offences are to be terminated as a result of the investigations conducted and based on the sources of information set out hereafter and on the reasons given in detail hereafter. 
Germany, Federal Court of Justice, Federal Prosecutor General, Fuel Tankers case, Decision, 16 April 2010, p. 1.
The Federal Prosecutor General also stated:
Criminal responsibility under § 211 StGB [i.e. for murder under Germany’s Penal Code]
b)
Colonel (Oberst) Klein’s actions were lawful under international law and therefore justified under domestic criminal law …
cc)
Even considering the fact that the bombing killed civilians to be protected under the international law of armed conflict, the order to attack was lawful under international law.
(1)
… International humanitarian law … prohibits … attacks … against a military objective if at the time of the order to attack the anticipated civilian damage is out of proportion (“excessive” see Art. 51 para. 5 sub-para. b AP [1977 Additional Protocol] I) to the anticipated concrete and direct military advantage (see ICRC Customary International Humanitarian Law, 2005 – hereafter ICRC Customary IHL [Study] – p. 46ff). …
(3)
… Only if a commander refrained from taking feasible precautions in violation of international law (“feasible precaution”; see. Art. 57 para. 2 sub-para. a AP I; ICRC Customary IHL [Study] p. 51 ff.) and such precautions would have led to the anticipation of greater civilian collateral damage which then in fact materialized is thus relevant for an analysis of the proportionality of an attack. … In view of the circumstances known to Colonel (Oberst) Klein (distance to inhabited settlements, night time, presence of armed Taliban) and the informant’s statements, he considered the presence of protected civilians unlikely … Further feasible reconnaissance and precautionary measures (“feasible precautions”) were not promptly available in the concrete situation. 
Germany, Federal Court of Justice, Federal Prosecutor General, Fuel Tankers case, Decision, 16 April 2010, pp. 63–66.
Upon ratification of the 1977 Additional Protocol I, Germany stated that it understood the word “feasible” to mean “that which is practicable or practically possible, taking into account all circumstances ruling at the time, including humanitarian and military considerations”. 
Germany, Declarations made upon ratification of the 1977 Additional Protocol I, 14 February 1991, § 2.
In 2010, in the Fuel Tankers case, the Federal Prosecutor General at Germany’s Federal Court of Justice investigated whether war crimes or other crimes under domestic law had been committed in the course of an airstrike which was ordered by a colonel (Oberst) of the German armed forces against two tankers transporting fuel for the International Security Assistance Force in Afghanistan stolen by the Taliban near Kunduz and which resulted in the deaths of a number of civilians. The Federal Prosecutor General stated:
Pursuant to § 170 para. 2 StPO [Penal Procedure Code], the investigation proceedings which were initiated by the order of 12 March 2010 against Colonel (Oberst) Klein and Company Sergeant Major (Hauptfeldwebel) Wilhelm due to suspected offences under the VStGB [International Crimes Code] and other offences are to be terminated as a result of the investigations conducted and based on the sources of information set out hereafter and on the reasons given in detail hereafter. 
Germany, Federal Court of Justice, Federal Prosecutor General, Fuel Tankers case, Decision, 16 April 2010, p. 1.
The Federal Prosecutor General also stated:
C. Assessment of the evidence
Colonel (Oberst) Klein had no reason to doubt the correctness of the statements by the informant [that no civilians were near the fuel tankers]. …
Lastly, the individual orders by Colonel (Oberst) Klein concerning the arrangement of the military processes also show that he was at all times keen to avoid any civilian victims. Therefore, he ordered that the source was called at least seven times in order to explicitly ask who was present on the ground. He did not give these orders because he had doubts about the credibility of the source’s previous statements. Rather, he endeavoured to constantly double-check his understanding of the situation and to exclude that in the meantime had civilians moved to the tankers. Only after he was sure that the source’s statements corresponded to the video pictures transmitted by the aircrafts and that no further information from other sources was to be expected, did he decide to drop bombs on the fuel tankers. 
Germany, Federal Court of Justice, Federal Prosecutor General, Fuel Tankers case, Decision, 16 April 2010, p. 30.
In an explanatory memorandum submitted to the German Parliament in 1990 in the context of the ratification procedure of the Additional Protocols, the German Government stated:
Article 57 [of the 1977 Additional Protocol I] contains high requirements for military commanders. They can only evaluate the situation on the basis of facts at their disposal during the planning and execution of an attack. Military commanders cannot be held responsible on the basis of facts they did not know, and could not have known, and which became only clear afterwards. 
Germany, Lower House of Parliament, Explanatory memorandum on the Additional Protocols to the Geneva Conventions, BT-Drucksache 11/6770, 22 March 1990, p. 113.
Upon ratification of the 1977 Additional Protocol I, Germany stated:
It is the understanding of the Federal Republic of Germany that in the application of the provisions of Part IV, Section I, of Additional Protocol I, to military commanders and others responsible for planning, deciding upon or executing attacks, the decision taken by the person responsible has to be judged on the basis of all information available to him at the relevant time, and not on the basis of hindsight. 
Germany, Declarations made upon ratification of the 1977 Additional Protocol I, 14 February 1991, § 4.