United States of America
Practice Relating to Rule 1. The Principle of Distinction between Civilians and Combatants
The US Air Force Pamphlet (1976) states: “In order to insure respect and protection for the civilian population and civilian objects, the parties to the conflict must at all times distinguish between the civilian population and combatants.”
The US Naval Handbook (1995) states: “The law of armed conflicts is based largely on the distinction to be made between combatants and noncombatants.”
The US Naval Handbook (2007) states: “The principle of distinction is concerned with distinguishing combatants from civilians and military objects from civilian objects so as to minimize damage to civilians and civilian objects.”
In explaining the US Government’s position on the basic principles applicable in armed conflicts before the Third Committee of the UN General Assembly in 1968, the US representative stated that the principle of distinction, as set out in draft General Assembly Resolution 2444 (XXIII), constituted a reaffirmation of existing international law.
Subsequently, US officials have referred to General Assembly Resolution 2444 (XXIII) as an accurate statement of the customary rule that a distinction must be made at all times between persons taking part in hostilities and the civilian population.
In 1991, in response to an ICRC memorandum on the applicability of IHL in the Gulf region, the US Department of the Army pointed out that “the obligation of distinguishing combatants and military objectives from civilians and civilian objects is a shared responsibility of the attacker, defender, and the civilian population as such”.
In 1992, in its final report to Congress on the conduct of the Gulf War, the US Department of Defense stated that Article 48 of the 1977 Additional Protocol I “is generally regarded as a codification of the customary practice of nations, and therefore binding on all”.
The US Department of Defense also stated:
The law of war with respect to targeting, collateral damage and collateral civilian casualties is derived from the principle of discrimination; that is, the necessity for distinguishing between combatants, who may be attacked, and noncombatants, against whom an intentional attack may not be directed, and between legitimate military targets and civilian objects.
According to the Report on US Practice: “It is the
opinio juris of the United States that … a distinction must be made between persons taking part in the hostilities and the civilian population to the effect that the civilians be spared as much as possible.”
In March 2010, in a speech given at the Annual Meeting of the American Society of International Law, the US State Department’s Legal Adviser stated:
[T]his Administration has carefully reviewed the rules governing targeting operations to ensure that these operations are conducted consistently with law of war principles, including:
- First, the principle of distinction, which requires that attacks be limited to military objectives and that civilians or civilian objects shall not be the object of the attack;
…
In U.S. operations against al-Qaeda and its associated forces – including lethal operations conducted with the use of unmanned aerial vehicles – great care is taken to adhere to these principles in both planning and execution, to ensure that only legitimate objectives are targeted.

[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.
The US Rules of Engagement for Operation Desert Storm (1991) sets as a basic rule “fight only combatants”.
The US Naval Handbook (1995) states that only attacks against combatants and other military objectives are lawful.
The US Naval Handbook (2007) states: “Only military objectives may be attacked. Military objectives are combatants … ”.
The Handbook also states: “Lawful combatants … are subject to attack at anytime during hostilities unless they are
hors de combat.”
At the CDDH, the United States stated that the first sentence of Article 47(2) of the draft Additional Protocol I (now Article 52(2)) “prohibits only such attacks as may be directed against non-military objectives. It does not deal with the question of collateral damage caused by attacks directed against military objectives.”
In March 2010, in a speech given at the Annual Meeting of the American Society of International Law, the Legal Adviser of the US State Department stated:
Recently, a number of legal objections have been raised against U.S. targeting practices. …
First, some have suggested that the
very act of targeting a particular leader of an enemy force in an armed conflict must violate the laws of war. But individuals who are part of such an armed group are belligerents and, therefore, lawful targets under international law. During World War II, for example, American aviators tracked and shot down the airplane carrying the architect of the Japanese attack on Pearl Harbor, who was also the leader of enemy forces in the Battle of Midway. This was a lawful operation then, and would be if conducted today. Indeed, targeting particular individuals serves to narrow the focus when force is employed and to avoid broader harm to civilians and civilian objects.

[emphasis in original]
The US Air Force Pamphlet (1976) states that the “civilian population as such, as well as individual civilians, shall not be made the object of attack”.
The Pamphlet adds: “In addition to the grave breaches of the Geneva Conventions of 1949, the following acts are representative of situations involving individual criminal responsibility: … (4) Aerial bombardment for the deliberate purpose of killing protected civilians”.
The US Naval Handbook (1995) states: “Civilians and civilian objects may not be made the object of attack.”
The Handbook also states that carrying out a “bombardment, the sole purpose of which is to attack and terrorize the civilian population” is an example of a war crime.
The US Manual for Military Commissions (2007), Part IV, Crimes and Elements, includes in the list of crimes triable by military commissions:
ATTACKING CIVILIANS.
a. Text. “Any person subject to this chapter who intentionally engages in an attack upon a civilian population as such, or individual civilians not taking active part in hostilities, shall be punished, if death results to one or more of the victims, by death or such other punishment as a military commission under this chapter may direct, and, if death does not result to any of the victims, by such punishment, other than death, as a military commission under this chapter may direct.”
b. Elements.
(1) The accused engaged in an attack;
(2) The object of the attack was a civilian population as such, or individual civilians not taking direct or active part in hostilities;
(3) The accused intended the civilian population as such, or individual civilians not taking direct or active part in hostilities, to be an object of the attack;
(4) The accused knew or should have known of the factual circumstances that established the civilian status; and
(5) The attack took place in the context of and was associated with armed conflict.
c. Comment. The intent required for this offense precludes its applicability with regard to collateral damage or death, damage, or injury incident to a lawful attack.
d
. Maximum punishment. Death, if the death of any person occurs as a result of the attack on civilians. Otherwise, confinement for life.
The US Naval Handbook (2007) states: “Civilians … may not be made the object of deliberate or indiscriminate attack”.
The Handbook also states that examples of war crimes that could be considered as grave breaches of the 1949 Geneva Conventions include carrying out a “bombardment, the sole purpose of which is to attack and terrorize the civilian population”.
The US Manual for Military Commissions (2010), Part IV, Crimes and Elements, defines a protected person as follows:
The term “protected person” means any person entitled to protection under one or more of the Geneva Conventions, including—
(A) civilians not taking an active part in hostilities.
The manual includes in the list of crimes triable by military commissions:
ATTACKING CIVILIANS.
a. Text. “Any person subject to this chapter who intentionally engages in an attack upon a civilian population as such, or individual civilians not taking active part in hostilities, shall be punished, if death results to one or more of the victims, by death or such other punishment as a military commission under this chapter may direct, and, if death does not result to any of the victims, by such punishment, other than death, as a military commission under this chapter may direct.”
b. Elements.
(1) The accused engaged in an attack;
(2) The object of the attack was a civilian population as such, or individual civilians not taking direct or active part in hostilities;
(3) The accused intended the civilian population as such, or individual civilians not taking direct or active part in hostilities, to be an object of the attack;
(4) The accused knew or should have known of the factual circumstances that established the civilian status; and
(5) The attack took place in the context of and was associated with hostilities.
c. Comment. The intent required for this offense precludes its applicability with regard to collateral damage or death, damage, or injury incident to a lawful attack.
d.
Maximum punishment. Death, if the death of any person occurs as a result of the attack on civilians. Otherwise, confinement for life.
The US Military Commissions Act (2006), passed by Congress following the US Supreme Court’s decision in Hamdan v. Rumsfeld in 2006, amends Title 10 of the United States Code as follows:
“§ 950v. Crimes triable by military commissions
“(a) DEFINITIONS AND CONSTRUCTION. – In this section:
“ …
“(2) PROTECTED PERSON. – The term “protected person” means any person entitled to protection under one or more of the Geneva Conventions, including –
“(A) civilians not taking an active part in hostilities.
The Act further states:
“(b) OFFENSES. – The following offenses shall be triable by military commission under this chapter at any time without limitation:
“ …
“(2) ATTACKING CIVILIANS. – Any person subject to this chapter who intentionally engages in an attack upon a civilian population as such, or individual civilians not taking active part in hostilities, shall be punished, if death results to one or more of the victims, by death or such other punishment as a military commission under this chapter may direct, and, if death does not result to any of the victims, by such punishment, other than death, as a military commission under this chapter may direct.
The US Military Commissions Act (2009) amends Chapter 47A of Title 10 of the United States Code as follows:
“§ 950p. Definitions; construction of certain offenses; common circumstances
“(a) DEFINITIONS.—In this subchapter:
“ …
“(2) The term “protected person” means any person entitled to protection under one or more of the [1949] Geneva Conventions, including civilians not taking an active part in hostilities …
The Act also states:
“§ 950t. Crimes triable by military commission
“The following offenses shall be triable by military commission under this chapter at any time without limitation:
“ …
“(2) ATTACKING CIVILIANS.—Any person subject to this chapter who intentionally engages in an attack upon a civilian population as such, or individual civilians not taking active part in hostilities, shall be punished, if death results to one or more of the victims, by death or such other punishment as a military commission under this chapter may direct, and, if death does not result to any of the victims, by such punishment, other than death, as a military commission under this chapter may direct.
On 1 September 1939, the US President wrote to the Governments of France, Germany, Italy, Poland and the United Kingdom asking “every government which may be engaged in hostilities publicly to affirm its determination that its armed forces shall in no event, and under no circumstances, undertake the bombardment from the air of civilian populations”.
In 1972, the General Counsel of the US Department of Defense considered that the prohibition on launching attacks against the civilian population was a general principle of the law of armed conflict which was declaratory of existing customary international law.
In 1974, at the Lucerne Conference of Government Experts on Weapons which may Cause Unnecessary Suffering or have Indiscriminate Effects, the head of the US delegation stated: “The law of war also prohibits attacks on civilians and civilian objects as such. This unchallenged principle is that civilians (and persons
hors de combat) whether in occupied territory or elsewhere must not be made the object of attack.”
In 1991, in a diplomatic note to Iraq concerning operations in the Gulf War, the United States stated: “The civilian population, as such, as well as individual civilians, should not be the object of attack.”
In another such diplomatic note, the United States reiterated: “the civilian population, as such, is not the object of attack”.
In 1991, in a report submitted to the UN Security Council on operations in the Gulf War, the United States stated: “Over 52,000 coalition air sorties have been carried out since hostilities began on 16 January. These sorties were not flown against any civilian or religious targets or against the Iraqi civilian population.”
In 1992, in its final report to Congress on the conduct of the Gulf War, the US Department of Defense stated: “As a general principle, the law of war prohibits … the direct, intentional attack of civilians not taking part in hostilities”.
In several reports submitted in 1992 to the UN Security Council pursuant to paragraph 5 of Security Council Resolution 771 (1992) on grave breaches of the 1949 Geneva Convention IV committed in the former Yugoslavia, the United States described “deliberate attacks on non-combatants” perpetrated by the parties to the conflict.
In its written statement submitted to the ICJ in the
Nuclear Weapons case in 1995, the United States stated: “The law of armed conflict precludes making civilians the object of attack as such.”
According to the Report on US Practice: “It is the
opinio juris of the United States that it is prohibited to launch attacks against the civilian population as such.”