Related Rule
Germany
Practice Relating to Rule 6. Civilians’ Loss of Protection from Attack
Germany’s Military Manual (1992) states: “Civilians who do not take part in hostilities shall be respected and protected.” 
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 KonfliktenHandbuch, August 1992, § 502.
The manual further states: “Persons taking a direct part in hostilities are not entitled to claim the rights accorded to civilians by international humanitarian law.” 
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 KonfliktenHandbuch, August 1992, § 517.
Germany’s Soldiers’ Manual (2006) states:
Civilians may not take part in combat operations.
Civilians who do not take part in combat operations shall be respected and protected. They may neither be attacked nor killed, wounded or captured. 
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.
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 (ISAF) 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 …
In the assessment of the lawfulness of military attacks in non-international armed conflict which result in the killing of persons, the victims’ status under the international law of armed conflict is of particular relevance. One must distinguish whether the victims are armed fighters of the adverse party, civilians directly participating in hostilities, or other civilians. Persons who belong to the first two categories are in principle legitimate targets of military attacks.
bb)
… [A]ll victims of the bombing, as long as they were not members of the Taliban, were civilians to be protected under international humanitarian law and not civilians who were directly participating in hostilities and who would have been lawful military objectives (see Art. 51 para. 3 API [1977 Additional Protocol I]). This is also true for both the people who were helping the Taliban to free the tankers [which were immobilized on a sandbank] and those trying to obtain fuel for their private gain.
(1)
The notion of hostilities is not defined in the international conventions, but taken as a given. International State practice, jurisprudence and literature have, however, largely clarified its meaning … Hostilities are thus not only understood in the narrow sense as armed acts of destroying personnel and equipment of the adverse forces … Rather, the term also comprises all acts which negatively affect the military capacities and operations of a party to the conflict, with a direct causal link between the act and the disadvantage caused and an objective link (belligerent nexus) between the damage caused to the adversary and the advantage for the opposing party being required … Consequently, acts of sabotage, the disruption of the enemy’s logistics and communications are covered …, whereas the general disruption of a the civilian infrastructure of the country in which the armed conflict is taking place, even if negatively affecting the enemy forces, is not. … The direct participation in hostilities as understood under the international law of armed conflict is independent of the individual will of the person concerned because the temporary loss of protection as a civilian is the consequence of the person objectively constituting a military threat … The question whether individual civilians were forced by the Taliban to support them or if children below the permissible age of recruitment were among them … is thus irrelevant for the legal evaluation. For the purposes of a direct participation in hostilities it is also irrelevant whether a civilian committed crimes through his actions (which seems to be the case here either through the handling of stolen goods or the participation in a murder with robbery depending on the individual case). …
(2)
The civilians siphoning fuel from the tankers for their private gain and not in support of the Taliban were therefore clearly not directly participating in hostilities. Regarding the civilians who were supporting the Taliban, it must be taken into account that the abduction of the two fuel tankers which had been designated for ISAF forces in principle constitutes causing damage to the military capacities as comprised in the notion of hostilities. The requirement of a nexus … between the damage and the advantage for the other party to the conflict was also fulfilled. However, the requirement of direct causality between the act and the damage was not fulfilled … Regarding the significant resource of fuel, a disadvantage for a party to the conflict can be found in two respects: On the one hand the loss of own material, on the other hand the strengthening of the adversary’s resources. In both respects the direct causality between the act and the disadvantage must be particularly examined.
Regarding the loss of fuel, the proximity to the party to the conflict and the use in armed conflict is decisive. In the present case, the fuel was intended for the ISAF forces, but was still in the possession of a private logistics company and was located far away from the point of destination. The necessary relationship of proximity is therefore not fulfilled.
The requirement of strengthening a party to the conflict with the consequence of directly harming the adverse party is not fulfilled in the present case either. The situation corresponds to a general strengthening of the resources of one party without direct relation to the hostilities, as is the case with supporting the Taliban by financial donations … or by smuggling weapons and ammunition across the border … If the strengthening of military capacities directly resulted in concrete military operations, for example by transporting weapons directly to an area where they will be used … , the assessment would be different. This is not pertinent in the present case because the Taliban’s goal was to transfer the stolen fuel tankers to an area under their control. 
Germany, Federal Court of Justice, Federal Prosecutor General, Fuel Tankers case, Decision, 16 April 2010, pp. 59–63.
In 2010, in reply to a Minor Interpellation in the Bundestag (Lower House of Parliament) titled “Compensation for the victims of the Kunduz bombardment in the night of 4 September 2009”, Germany’s Federal Government wrote:
5. Based on which criteria and evidence does the Federal Government conclude that a person is to be considered an “enemy fighter” and in which way is the principle of the [1977] Additional Protocol I to the Geneva Conventions, which states that in case of doubt a person is to be considered a civilian, taken into consideration?
In the context of a non-international armed conflict, international humanitarian law permits governmental troops and troops supporting them to use direct military force against civilians directly participating in concrete hostilities … . Whether a person fulfils these conditions depends on the circumstances of the individual case. 
Germany, Lower House of Federal Parliament (Bundestag), Reply by the Federal Government to the Minor Interpellation by Members Christine Buchholz, Sevim Dağdelen, Inge Höger, further Members and the Parliamentary Group DIE LINKE, BT-Drs. 17/3723, 11 November 2010, p. 3.
In 2010, in reply to a Minor Interpellation in the Bundestag (Lower House of Parliament) titled “Killing of German nationals by a US drone attack – Intervention of the German judiciary”, the Federal Government wrote:
15. How does the Federal Government evaluate the legality of acts of targeted killing of persons within the context of international and non-international armed conflicts …?
International humanitarian law distinguishes in international and non-international armed conflicts between, on the one hand, armed forces opposing one another (international armed conflict) or armed forces and opposed organized armed groups (non-international [armed conflict]) and, on the other hand, civilians.
… [C]ivilians may in principle not be directly attacked and only lose protection from attack if and for such time as they directly participate in hostilities. 
Germany, Lower House of Federal Parliament (Bundestag), Reply by the Federal Government to the Minor Interpellation by Members Jerzy Montag, Hans-Christian Ströbele, Omit Nouripour, further Members and the Parliamentary Group BÜNDNIS 90/DIE GRÜNEN, BT-Drs. 17/3916, 23 November 2010, p. 6.
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)
The anticipated civilian collateral damages are also to be assessed from the perspective of the attacker at the time of the attack, rather than with hindsight according to the actual unfolding of events (see also the wording of Art. 51 para. 5 sub-para. b AP I … “may be expected”; ICRC Customary IHL [Study] p. 50 …). … The international law of armed conflict requires that in case of doubt a person is to be considered a civilian (see Art. 50 para. 1 sentence 2 AP I). However, there is no such case of doubt if – as is the case here – there are sufficient indications, considering the concrete circumstances, that the persons concerned are a legitimate objective of a military attack; absolute certainty is not necessary. 
Germany, Federal Court of Justice, Federal Prosecutor General, Fuel Tankers case, Decision, 16 April 2010, pp. 63–66.