Related Rule
Israel
Practice Relating to Rule 14. Proportionality in Attack
With reference to Israel’s Law of War Booklet (1997), the Report on the Practice of Israel states: “The IDF [Israel Defense Forces] would not attack a target in cases in which it is expected that the attack would cause civilian loss, injury or damage excessive in relation to the military advantage anticipated.” 
Report on the Practice of Israel, 1997, Chapter 1.5, referring to Conduct in the Battlefield in Accordance with the Law of War, Israel Defense Forces, 1986, pp. 4–5.
Israel’s Manual on the Laws of War (1998) states:
Even when it is not possible to isolate the civilians from an assault and there is no other recourse but to attack, this does not constitute a green light to inflict unbridled harm on civilians. The commander is required to refrain from an attack that is expected to inflict harm on the civilian population that is disproportionate to the expected military gain. 
Israel, Laws of War in the Battlefield, Manual, Military Advocate General Headquarters, Military School, 1998, p. 40.
Israel’s Manual on the Rules of Warfare (2006) states:
In any attack, it is a duty to ensure that:
- That the military gain expected from the attack is proportional to the expected damage that would be caused to civilians as a result of the offensive. 
Israel, Rules of Warfare on the Battlefield, Military Advocate-General’s Corps Command, IDF School of Military Law, Second Edition, 2006, p. 26.
The manual further states: “Proportionality must be maintained: an act must not be performed if the damage to civilians/the environment exceeds the concomitant military benefit.” 
Israel, Rules of Warfare on the Battlefield, Military Advocate-General’s Corps Command, IDF School of Military Law, Second Edition, 2006, p. 49.
The Manual on the Rules of Warfare (2006) is a second edition of the Manual on the Laws of War (1998).
In its judgment in the Public Committee against Torture in Israel case in 2006, Israel’s High Court of Justice stated:
A. The Principle of Proportionality and its Application in Customary International Law
41. The principle of proportionality is a general principle in law. It is part of our legal conceptualization of human rights … It is an important component of customary international law … It is an integral part of the law of self defense. It is a substantive component in protection of civilians in situations of armed conflict … It is a central part of the law of belligerent occupation … In a long list of judgments, the Supreme Court has examined the authority of the military commander in the area according to the standards of proportionality. It has done so, inter alia, regarding restriction of place of residence (Ajuri); regarding encirclement of villages and positioning checkpoints on the access roads to and from them in order to frustrate terrorism (HCJ 2847/03 Alauna v. The Commander of IDF Forces in Judea and Samaria (unpublished)); regarding harm to property of protected persons due to army operations (see HCJ 9525/00 Ali Skai v. The State of Israel (unpublished)); regarding the safeguarding of freedom of worship and the right to access to holy places (Hass); regarding demolition of houses due to operational needs (see HCJ 4219/02 Gusin v. The Commander of IDF Forces in the Gaza Strip, 56(4) PD 608); regarding the laying of siege (Almandi); regarding the erection of the security fence (Beit Sourik; Maraabe).
B. Proportionality in an International Armed Conflict
42. The principle of proportionality is a substantial part of international law regarding armed conflict (compare §51(5)(b) and 57 of The First Protocol [1977 Additional Protocol I] … That law is of customary character (see Prosecutor v. Kupreskic, ICTY Case no. IT-95-16 (2000)). The principle of proportionality arises when the military operation is directed toward combatants and military objectives, or against civilians at such time as they are taking a direct part in hostilities, yet civilians are also harmed. The rule is that the harm to innocent civilians caused by collateral damage during combat operations must be proportionate … Civilians might be harmed due to their presence inside of a military target, such as civilians working in an army base; civilians might be harmed when they live or work in, or pass by, military targets; at times, due to a mistake, civilians are harmed even if they are far from military targets; at times civilians are forced to serve as “human shields” from attack upon a military target, and they are harmed as a result. In all those situations, and in other similar ones, the rule is that the harm to the innocent civilians must fulfill, inter alia, the requirements of the principle of proportionality.
43. The principle of proportionality applies in every case in which civilians are harmed at such time as they are not taking a direct part in hostilities. Judge Higgins pointed that out in the Legality of Nuclear Weapons case:
“The principle of proportionality, even if finding no specific mention, is reflected in many provisions of Additional Protocol I to the Geneva Conventions of 1949. Thus even a legitimate target may not be attacked if the collateral civilian casualties would be disproportionate to the specific military gain from the attack” (p. 587).
A manifestation of this customary principle can be found in The First Protocol, pursuant to which indiscriminate attacks are forbidden § 51(4)). The First Protocol further determines (§51(5)):
Among others, the following types of attacks are to be considered as indiscriminate:
(a) …
(b) An attack which may be expected to cause incidental loss of civilian life, injury to civilians, damage to civilian objects, or a combination thereof, which would be excessive in relation to the concrete and direct military advantage anticipated.
44. The requirement of proportionality in the laws of armed conflict focuses primarily upon what our constitutional law calls proportionality “stricto senso”, that is, the requirement that there be a proper proportionate relationship between the military objective and the civilian damage. However, the laws of armed conflict include additional components, which are also an integral part of the theoretical principle of proportionality in the wider sense. The possibility of concentrating that law into the legal category to which it belongs, while formulating a comprehensive doctrine of proportionality, as is common in the internal law of many states, should be considered. That cannot be examined in the framework of the petition before us. We shall concentrate upon the aspect of proportionality which is accepted, without exception, as relevant to the subject under discussion. 
Israel, High Court of Justice, Public Committee against Torture in Israel case, Judgment, 14 December 2006, §§ 41–44.
In 2006, Israel’s Ministry of Foreign Affairs stated:
3. Proportionality
The second legal requirement is that the potential harm to civilians and civilian objects expected in any attack must be proportionate to the military advantage anticipated.
Major General A.P.V. Rogers, a former Director of British Army Legal Services, explains the rationale behind this principle:
Although they are not military objectives, civilians and civilian objects are subject to the general dangers of War in the sense that attacks on military personnel and military objectives may cause incidental damage. It may not be possible to limit the radius of effect entirely to the objective to be attacked … Members of the armed forces are not liable for such incidental damage, provided it is proportionate to the military gain expected of the attack.
While the principle is clear, in practice weighing the expected military advantage against possible collateral damage can be an extremely complex, especially in the heat of an armed conflict. In their report to the Prosecutor of the International Criminal Tribunal for the former Yugoslavia, the Committee established to review NATO bombings in Yugoslavia highlighted the particular difficulties which arise when military objectives are located in densely populated areas:
The answers to these questions are not simple. It may be necessary to resolve them on a case by case basis, and the answers may differ depending on the background and values of the decision maker. It is unlikely that a human rights lawyer and an experienced combat commander would assign the same relative values to military advantage and to injury to noncombatants. … It is suggested that the determination of relative values must be that of the “reasonable military commander.”
One important principle established by international law for the “reasonable military commander” seeking to make this difficult balance, is that the proportionality of a response to an attack is to be measured not in regard to the specific attack suffered by a state but in regard to what is necessary to remove the overall threat. As Rosalyn Higgins, currently President of the International Court of Justice, has written, proportionality:
cannot be in relation to any specific prior injury – it has to be in relation to the overall legitimate objective of ending the aggression
Accordingly, the right of self-defense includes not only acts taken to prevent the immediate threat, but also to prevent subsequent attacks.
… in relation to the question of proportionality, the IDF Manual states:
Even when it is not possible to isolate the civilians from an assault and there is no other recourse but to attack, the commander is required to refrain from an attack that is expected to inflict harm on the civilian population, which is disproportionate to the expected military gain. 
Israel, Responding to Hizbullah Attacks from Lebanon: Issues of Proportionality, Legal Background, Ministry of Foreign Affairs of Israel, 25 July 2006, §§ 3–4.
In 2007, Israel’s Ministry of Foreign Affairs stated in a diplomatic note:
Proportionality
A further legal requirement is that the potential harm to civilians and civilian objects expected in any attack must be proportionate to the military advantage anticipated.
Major General A.P.V. Rogers, a former Director of British Army Legal Services, explains the rationale behind this principle:
Although they are not military objectives, civilians and civilian objects are subject to the general dangers of War in the sense that attacks on military personnel and military objectives may cause incidental damage. It may not be possible to limit the radius of effect entirely to the objective to be attacked … Members of the armed forces are not liable for such incidental damage, provided it is proportionate to the military gain expected of the attack.
While the principle is clear, in practice weighing the expected military advantage against possible collateral damage can be an extremely complex, especially in the heat of an armed conflict. In their report to the Prosecutor of the International Criminal Tribunal for the former Yugoslavia, the Committee established to review NATO bombings in Yugoslavia highlighted the particular difficulties which arise when military objectives are located in densely populated areas:
The answers to these questions are not simple. It may be necessary to resolve them on a case by case basis, and the answers may differ depending on the background and values of the decision maker. It is unlikely that a human rights lawyer and an experienced combat commander would assign the same relative values to military advantage and to injury to noncombatants. … It is suggested that the determination of relative values must be that of the “reasonable military commander.”
The test of proportionality to be applied in a case of armed conflict (jus in bellum) is broader that that applied under the principles of self-defense outside the context of actual warfare (jus ad bellum). But it should be noted that the policies applied in practice by the IDF conformed even with this stricter test of proportionality. In relation to the self-defense standard, it should be recalled that international law provides that the proportionality of a response to an attack is to be measured, not in regard to the specific attack suffered by a state, but in regard to what is necessary to remove the overall threat. As Rosalyn Higgins, currently President of the International Court of Justice, has written, proportionality:
cannot be in relation to any specific prior injury – it has to be in relation to the overall legitimate objective of ending the aggression
Accordingly, the right of self-defense includes not only acts implemented to prevent the immediate threat, but also to prevent subsequent attacks”. In Israel’s case this means that its response had to be measured not only in respect to the initial Hizbullah cross-border attack, or even the 4,000 missiles fired at Israel’s northern towns and villages, but also against the threat of the tens of thousands of missiles which Hizbullah had amassed and continued to receive from Iran and Syria.
… in relation to the question of proportionality, the IDF position is clear:
Even when it is not possible to isolate the civilians from an assault and there is no other recourse but to attack, the commander is required to refrain from an attack that is expected to inflict harm on the civilian population, which is disproportionate to the expected military gain. 
Israel, Israel’s War with Hizbullah. Preserving Humanitarian Principles While Combating Terrorism, Diplomatic Notes No. 1, Ministry of Foreign Affairs of Israel, April 2007, pp. 11–13.
In 2008, in a briefing to the Diplomatic Corps on Israel’s operations in Gaza, Israel’s Vice Prime Minister and Minister of Foreign Affairs stated:
I think that Israel is the only state in the world in which its Minister of Defense has today, during a time of almost war, met with the Attorney General, the Minister of Justice, and Foreign Ministry experts on international law, in order to speak about and understand the terms of proportionality in accordance with how the IDF [Israel Defense Forces] works and will continue to work on the ground. So, basically, it is not something that can be judged. I hope that the international community knows that we are trying to avoid civilian casualties … .
Now, it comes down to different examples. We can discuss them. The situation in which you have a family living in a factory where I know there are rockets that can kill Israelis – is this proportionate action? I think that it is proportionate. But these are the decisions that the Israeli Chief of Staff needs to decide on a daily basis.
So, yes, I believe that what we are doing is proportionate but I don’t know how you can measure proportionality when you are in this kind of situation. In a way, a war against terrorism is unfair because, on one side, there are these terrorists. Believe me, proportionality is something that isn’t part of their vocabulary, and international law is not part of their vocabulary and the Geneva Convention is not part of their vocabulary. We are working with our hands tied because of all these rules, and because we are part of the free world, and because this is part of our values as well. But accidents can happen and civilians are also being killed by Israeli operations. I am not going to ignore it but I hope that there is a better understanding of what we are trying to avoid. 
Israel, Briefing to the Diplomatic Corps by the Vice Prime Minister and Minister of Foreign Affairs, 3 March 2008.
In 2008, in a background paper on Israel’s operations in Gaza, Israel’s Ministry of Foreign Affairs stated:
In practice, two key questions arise in relation to the legitimacy of the … execution of an operation: 1) Is the target itself a legitimate military objective? and 2) Even if the target is in itself legitimate, is there likely to be disproportionate injury and damage to the civilian population and civilian property.
3. Proportionality
The second legal requirement is that any attack be proportionate, in the sense that incidental loss and damage expected to be caused to civilians and civilian objects must not be excessive in relation to the military advantage anticipated.
While the principle is clear, in practice weighing an expected military advantage against possible collateral damage can be an extremely complex calculation to make, especially in the heat of an armed conflict. In their report to the Prosecutor of the International Criminal Tribunal for the former Yugoslavia, the Committee established to review NATO bombings in Yugoslavia highlighted the particular difficulties which arise when military objectives are located in densely populated areas:
The answers to these questions are not simple. It may be necessary to resolve them on a case by case basis, and the answers may differ depending on the background and values of the decision maker. It is unlikely that a human rights lawyer and an experienced combat commander would assign the same relative values to military advantage and to injury to non-combatants. … It is suggested that the determination of relative values must be that of the “reasonable military commander”. [Final Report to the Prosecutor by the Committee established to review NATO bombings in Yugoslavia para. 50-1]
Furthermore, in making this determination, a military commander is not required to ignore questions relating to the safety of his own forces. To the contrary, As Bothe et al note:
The concept of military advantage involves a variety of considerations including the security of the attacking force. ibid
4. From theory to practice – Israel’s operations in Gaza
Similarly, in relation to the question of proportionality, IDF [Israel Defense Forces] doctrine requires a commander to refrain from an attack that is expected to inflict incidental harm on the civilian population that is excessive in proportion to the expected military gain. In practice this requires the IDF and the commander in the field to assess both the expected military gain and the potential of collateral injury to civilians in the area. 
Israel, Ministry of Foreign Affairs, Background paper, Responding to Hamas Attacks from Gaza: Issues of Proportionality, December 2008, §§ 1 and 3–4.
[footnotes in original omitted]
In 2009, in a report on Israeli operations in Gaza between 27 December 2008 and 18 January 2009 (the “Gaza Operation”, also known as “Operation Cast Lead”), Israel’s Ministry of Foreign Affairs stated:
120. In addition to the principle of distinction, customary international law bars military attacks that are anticipated to harm civilians excessively in relation to the expected military advantage. This principle, known as the “principle of proportionality,” is reflected in [the 1977] Additional Protocol I [Article 51(5)(b)], which prohibits launching attacks “which may be expected to cause incidental loss of civilian life, injury 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 “elements of crimes” drafted in the Rome Statute of the International Criminal Court implementation process and approved by the Assembly of States Parties to the Rome [1998 ICC] Statute clarifies two key matters as well – that the actionable offence of causing “excessive incidental death, injury or damage” is established only where these matters were “clearly excessive,” and that excess and proportion is to be judged “in relation to the concrete and direct overall military advantage anticipated.” While Israel is not a party to either Additional Protocol I or the Rome Statute, it accepts these clarifications as reflective of customary international law.
121. The very notion of not inflicting “excessive” harm recognises that some civilian casualties may be unavoidable when pursuing legitimate military objectives. Numerous military manuals reflect this grim reality. …
122. By definition, then, evaluation of proportionality (or excessive harm to civilians compared to military advantage) requires balancing two very different sets of values and objectives, in a framework in which all choices will affect human life. States have duties to protect the lives of their civilians and soldiers by pursuing proper military objectives, but they must balance this against their duty to minimise incidental loss of civilian lives and civilian property during military operations. That balancing is inherently difficult, and raises significant moral and ethical issues. …
128. As with the principle of distinction, a showing of intent is required for there to have been any arguable “war crime” based on excessive civilian harm in comparison with military objectives. As customary international law is reflected in the specific relevant section of the Rome Statute, for example, it is clear that a war crime requires the “intentional launching” of an attack “in the knowledge that such attack will cause incidental loss of life or injury to civilians … which would be clearly excessive in relation to the concrete and direct overall military advantage anticipated.” In other words, from this very definition, the existence of a war crime turns not on the reasonableness of the commander’s weighing of military advantage against civilian harm, but on whether he or she knew that the attack would cause clearly disproportionate harm, but proceeded intentionally notwithstanding this knowledge.
129. In other words, there is no indication of a “war crime” simply because others conclude, after the conflict, that a different decision – often, a snap decision taken on the battlefield – could have led to fewer civilian casualties. To the contrary, if the commander in the field did not intend and did not know that the attack would cause clearly excessive levels of civil harm, there is no legal basis for labelling it as [a] war crime. 
Israel, Ministry of Foreign Affairs, The Operation in Gaza 27 December 2008–18 January 2009: Factual and Legal Aspects, 29 July 2009, §§ 120–122 and 128–129.
[emphasis in original; footnotes in original omitted]
The report also stated:
The issue of proportionality turns on the reasonableness of a commander’s decision to use a particular munition in a particular context, taking into account the expected military benefit and the expected collateral damage. Second-guessing the reasonableness of a commander’s decision in a rapidly evolving and complex battlefield situation should not be done lightly, and must take into account the information available to the commander at the time of the decision (not what actually occurred) and the value of the military objective to a reasonable commander (rather than to a third-party observer). 
Israel, Ministry of Foreign Affairs, The Operation in Gaza 27 December 2008–18 January 2009: Factual and Legal Aspects, 29 July 2009, § 421.
In 2010, in a position paper submitted to the Public Commission to Examine the Maritime Incident of 31 May 2010 (the Turkel Commission), established by the Israeli Government to examine the Gaza flotilla incident, Israel’s Military Advocate General stated:
In accordance with the principle of proportionality, the expectation that “civilians” will be killed and that “civilian objectives” will be hit in the framework of intentional attack against a legitimate military objective (human or object) does not make it illegal, despite that those “civilians” and “civilian objects” continue to be protected from attack intended to hit them. Such an attack constitutes a breach of the law of armed conflict only if as a result of it, collateral damage – including killing or wounding of “civilians” or damage to their property and to “civilian objectives” – which is disproportional to the military advantage expected to result from the attack, is expected to be caused. This conclusion does not change even when in the framework of the entirety of the combat, very many civilians are killed and wounded: even then, the high number of casualties, in and of itself, does not indicate that there was any breach of the law of armed conflict. To summarize, where activity is taking place in the legal framework of the law of armed conflict, the death of “civilians” does not, in and of itself, constitute a prima facie breach of the law of armed conflict; thus, it does not constitute cause for “setting into motion” the duty to investigate that is entrenched within. Only if suspicion arises that said result occurred as a result of an attack that was directed against those “civilians” (or against “civilian objectives”), with a goal of harming them per se, or as a result of an attack directed against a legitimate objective where it was known that it was likely to cause excessive collateral damage – can it be said that it is a prima facie breach of the principles of distinction and proportionality; and if it turns out that this indeed took place, and that the collateral damage that was expected to be caused thereby was clearly excessive, it is likely to lead to individual criminal liability, pursuant to international law; that is, it is liable to constitute a war crime.  
Israel, Position paper by the Military Advocate General on investigating allegations of violations of IHL, submitted to the Public Commission to Examine the Maritime Incident of 31 May 2010 (the Turkel Commission), 19 December 2010, Part B.
[emphasis in original]
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. 
Italy, 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.
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. 
Japan, 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.
Israel’s Manual on the Rules of Warfare (2006) states:
Upon attacking a military target that is located at the heart of [a] civilian district, for example, a group of enemy soldiers who are holed up in the heart of a city and surrounded by civilians, they may be attacked, but only if the expected military benefit to one’s side from the offensive exceeds the expected damage that might be caused to civilians. There is no set formula according to which it is possible to weigh the civilian damage against the expected military benefit from the offensive; but it is a question of degree. An offensive would not be considered legitimate if it presented a significant risk to many civilian lives in return for gaining a subordinate military objective. 
Israel, Rules of Warfare on the Battlefield, Military Advocate-General’s Corps Command, IDF School of Military Law, Second Edition, 2006, p. 27.
The manual further states:
The rules of war have laid down a number of rules of engagement in a theatre of war containing civilians:
- Even if it is not possible to isolate civilians from the military target and there is no choice but to attack, the commanding officer is required to refrain from conducting an attack that could be expected to cause the civilian population damage that is disproportionate to the expected military gain. 
Israel, Rules of Warfare on the Battlefield, Military Advocate-General’s Corps Command, IDF School of Military Law, Second Edition, 2006, pp. 27–28.
The Manual on the Rules of Warfare (2006) is a second edition of the Manual on the Laws of War (1998).
In its judgment in the Public Committee against Torture in Israel case in 2006, Israel’s High Court of Justice stated:
Proper Proportion between Benefit and Damage
45. The proportionality test determines that attack upon innocent civilians is not permitted if the collateral damage caused to them is not proportionate to the military advantage (in protecting combatants and civilians). In other words, attack is proportionate if the benefit stemming from the attainment of the proper military objective is proportionate to the damage caused to innocent civilians harmed by it. That is a values based test. It is based upon a balancing between conflicting values and interests (see Beit Sourik, at p. 850; HCJ 7052/03 Adalah – The Legal Center Arab Minority Rights in Israel (unpublished, paragraph 74 of my judgment, hereinafter Adalah). It is accepted in the national law of various countries. It constitutes a central normative test for examining the activity of the government in general, and of the military specifically, in Israel. In one case I stated:
“Basically, this subtest carries on its shoulders the constitutional view that the ends do not justify the means. It is a manifestation of the idea that there is a barrier of values which democracy cannot surpass, even if the purpose whose attainment is being attempted is worthy” (HCJ 8276/05 Adalah - The Legal Center for Arab Minority Rights in Israel v. The Minister of Defense (unpublished, paragraph 30 of my judgment; see also ROBERT ALEXY, A THEORY OF CONSTITUTIONAL RIGHTS 66 (2002)).
As we have seen, this requirement of proportionality is employed in customary international law regarding protection of civilians (see CASSESE, at p. 418; Kretzmer, at p. 200; Ben-Naftali & Michaeli, at p. 278; see also Gardam; as well as §51(2)(III) of The First Protocol [1977 Additional Protocol I], which constitutes customary law). When the damage to innocent civilians is not proportionate to the benefit of the attacking army, the attack is disproportionate and forbidden.
46. That aspect of proportionality is not required regarding harm to a combatant, or to a civilian taking a direct part in the hostilities at such time as the harm is caused. Indeed, a civilian taking part in hostilities is endangering his life, and he might – like a combatant – be the objective of a fatal attack. That killing is permitted. However, that proportionality is required in any case in which an innocent civilian is harmed. Thus, the requirements of proportionality stricto senso must be fulfilled in a case in which the harm to the terrorist carries with it collateral damage caused to nearby innocent civilians. The proportionality rule applies in regards to harm to those innocent civilians (see § 51(5)(b) of The First Protocol). The rule is that combatants and terrorists are not to be harmed if the damage expected to be caused to nearby innocent civilians is not proportionate to the military advantage in harming the combatants and terrorists (see HENCKAERTS & DOSWALD-BECK, at p. 49). Performing that balance is difficult. Here as well, one must proceed case by case, while narrowing the area of disagreement. Take the usual case of a combatant, or of a terrorist sniper shooting at soldiers or civilians from his porch. Shooting at him is proportionate even if as a result, an innocent civilian neighbor or passerby is harmed. That is not the case if the building is bombed from the air and scores of its residents and passersby are harmed (compare DINSTEIN, at p. 123; GROSS, at p. 621). The hard cases are those which are in the space between the extreme examples. There, a meticulous examination of every case is required; it is required that the military advantage be direct and anticipated (see §57(2)(iii) of The First Protocol). Indeed, in international law, as in internal law, the ends do not justify the means. The state’s power is not unlimited. Not all of the means are permitted. The Inter-American Court of Human Rights pointed that out, stating:
“[R]egardless of the seriousness of certain actions and the culpability of the perpetrators of certain crimes, the power of the state is not unlimited, nor may the state resort to any means to attain its ends” (Velasquez Rodriguez v. Honduras, I/A Court H.R. (Ser. C.), No 4, 1, para. 154 (1988)).
However, when hostilities occur, losses are caused. The state’s duty to protect the lives of its soldiers and civilians must be balanced against its duty to protect the lives of innocent civilians harmed during attacks on terrorists. That balancing is difficult when it regards human life. It raises moral and ethical problems (see Asa Kasher & Amos Yadlin, Assassination and Preventative Killing, 25 SAIS REVIEW 41 (2005). Despite the difficulty of that balancing, there’s no choice but to perform it. 
Israel, High Court of Justice, Public Committee against Torture in Israel case, Judgment, 14 December 2006, §§ 45–46.
In 2006, Israel’s Ministry of Foreign Affairs stated:
In practice, [the principle of proportionality] requires that the IDF [Israel Defense Forces] and the commander in the field assess both the expected military gain, and the potential of collateral injury to Lebanese civilians. With regard to the expected military gain, it should be noted that the relevant advantage is not that of that specific attack but of the military operation as a whole. As the German Military Manual points out:
The term “military advantage” refers to the advantage which can be expected of an attack as a whole and not only of isolated or specific parts of the attack.
It should also be recalled that, as noted above, the relevant consideration to gauge the legitimacy of a response to an act of aggression is not the attacks which have already been committed, but the “overall objective of ending the aggression”. In Israel’s case this means that its response has to be measured not only in respect of the initial Hizbullah cross-border attack, or even the missiles which have already been fired at Israel’s northern towns and villages (some 2,500 at time of writing), but also against the threat of the estimated 13,000 missiles which Hezbollah still has and threatens to use against Israel. 
Israel, Responding to Hizbullah Attacks from Lebanon: Issues of Proportionality, Legal Background, Ministry of Foreign Affairs of Israel, 25 July 2006, § 4.
In 2007, Israel’s Ministry of Foreign Affairs stated in a diplomatic note:
In practice, [the principle of proportionality] requires that the IDF [Israel Defense Forces] and the commander in the field assess both the expected military gain, and the potential of collateral injury to Lebanese civilians. With regard to the expected military gain, it should be noted that the relevant advantage is not that of that specific attack but of the military operation as a whole. As the German Military Manual points out:
The term “military advantage” refers to the advantage which can be expected of an attack as a whole and not only of isolated or specific parts of the attack. 
Israel, Israel’s War with Hizbullah. Preserving Humanitarian Principles While Combating Terrorism, Diplomatic Notes No. 1, Ministry of Foreign Affairs of Israel, April 2007, pp. 13–14.
In 2009, in a report on Israeli operations in Gaza between 27 December 2008 and 18 January 2009 (the “Gaza Operation”, also known as “Operation Cast Lead”), Israel’s Ministry of Foreign Affairs stated:
123. … [I]nternational law confirms the need to assess proportionality from the standpoint of a “reasonable military commander,” possessed of such information as was available at the time of the targeting decision and considering the military advantage of the attack as a whole. Moreover, the balancing may not be second-guessed in hindsight, based on new information that has come to light; it is a forward-looking test based on expectations and information at the time the decision was made. This perspective is confirmed by the use of the word “anticipated” within the text of the rule itself, as well as in the explanations provided by numerous States in ratifying [the 1977] Additional Protocol I.
126. The same criteria for assessing “military advantage” apply in the proportionality context, namely that the “military advantage anticipated” from a particular targeting decision must be considered from the standpoint of the overall objective of the mission. In addition, it may legitimately include not only the need to neutralise the adversary’s weapons and ammunition and dismantle military or terrorist infrastructure, but also – as a relevant but not overriding consideration – protecting the security of the commander’s own forces.
127. The standard does not penalise commanders for making close calls. Rather, it is intended to prohibit “manifestly disproportionate collateral damage inflicted in order to achieve operational objectives,” because this results in the action essentially being a “form of indiscriminate warfare.” 
Israel, Ministry of Foreign Affairs, The Operation in Gaza 27 December 2008–18 January 2009: Factual and Legal Aspects, 29 July 2009, §§ 123 and 126–127.
[emphasis in original; footnotes in original omitted]
In 2009, in a report on Israeli operations in Gaza between 27 December 2008 and 18 January 2009 (the “Gaza Operation”, also known as “Operation Cast Lead”), Israel’s Ministry of Foreign Affairs stated that “the core question, in assessing a commander’s decision to attack, will be (a) whether he or she made the determination on the basis of the best information available, given the circumstances, and (b) whether a reasonable commander could have reached a similar conclusion”. 
Israel, Ministry of Foreign Affairs, The Operation in Gaza 27 December 2008–18 January 2009: Factual and Legal Aspects, 29 July 2009, § 125.