Related Rule
United Kingdom of Great Britain and Northern Ireland
Practice Relating to Rule 7. The Principle of Distinction between Civilian Objects and Military Objectives
The UK LOAC Manual (2004) states: “Parties to the conflict shall at all times distinguish between civilians or other protected persons and combatants and between civilian or exempt objects and military objectives.” 
United Kingdom, The Manual of the Law of Armed Conflict, Ministry of Defence, 1 July 2004, § 12.19; see also § 13.25 (maritime warfare).
With regard to internal armed conflict, the manual states:
15.9. Attacks are to be directed only against objects or areas which, at the time the attack is launched, are of tactical or strategic military importance.
15.9.1. There is no definition of military objectives or attacks in the treaty law dealing with non-international armed conflicts. Nevertheless, the definitions used in respect of international armed conflicts should be treated as applicable. 
United Kingdom, The Manual of the Law of Armed Conflict, Ministry of Defence, 1 July 2004, §§ 15.9.– 15.9.1.
The UK LOAC Manual (2004), as amended in 2010, states:
Since military operations are to be conducted only against the enemy’s armed forces and military objectives, there must be a clear distinction … between objects that might legitimately be attacked and those that are protected from attack. The principle of distinction … separates legitimate targets, namely military objectives, from civilian objects. 
United Kingdom, The Manual of the Law of Armed Conflict, Ministry of Defence, 1 July 2004, as amended by Amendment 3, Ministry of Defence, September 2010, §§ 2.5–2.5.1.
15.9. Attacks are to be directed only against objects or areas which, at the time the attack is launched, are of tactical or strategic military importance so as to amount to military objectives. 
United Kingdom, The Manual of the Law of Armed Conflict, Joint Services Publication 383, Ministry of Defence, 1 July 2004, as amended by Amendment 7, Ministry of Defence, May 2013, § 15.9.
In reply to a question in the House of Lords concerning the Gulf War, the UK Parliamentary Under-Secretary of State of the Ministry of Defence stated:
The Geneva Conventions contain no provisions expressly regulating targeting in armed conflict. The Hague Regulations of 1907 and customary international law do, however, incorporate the twin principles of distinction between military and civilian objects, and of proportionality so far as the risk of collateral civilian damage from an attack on a military objective is concerned. These principles and associated rules of international law were observed at all times by coalition forces in the planning and execution of attacks against Iraq. 
United Kingdom, House of Lords, Statement by the Parliamentary Under-Secretary of State for Defence, 22 July 1991, Hansard, Vol. 531, Written Answers, col. 43.
In its written statement submitted to the ICJ in the Nuclear Weapons case in 1995, the United Kingdom stated: “The parties to an armed conflict are required to discriminate between civilians and civilian objects on the one hand and combatants and military objectives on the other and to direct their attacks only against the latter.” 
United Kingdom, Written statement submitted to the ICJ, Nuclear Weapons case, 16 June 1995, § 3.67.
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. 
United Kingdom, 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.
The UK Military Manual (1958) provides:
283. Bombardment and siege of defended localities are legitimate means of warfare. …
288. In defended towns and localities modern methods of bombardment will inevitably destroy many buildings and sites which are not military objectives. Such destruction, if incidental to the bombardment of military objectives is not unlawful. For example the bombardment of a war factory area may well destroy the houses of workers living in that area. If, on the other hand, bombardment is directed solely against a non-military objective, it is unlawful. 
United Kingdom, The Law of War on Land being Part III of the Manual of Military Law, The War Office, HMSO, 1958, Articles 283 and 288.
The UK LOAC Pamphlet (1981) provides: “Military operations may only be directed against military objectives.” 
United Kingdom, The Law of Armed Conflict, D/DAT/13/35/66, Army Code 71130 (Revised 1981), Ministry of Defence, prepared under the Direction of The Chief of the General Staff, 1981, Section 4, p. 13, § 4(a).
The UK LOAC Manual (2004) states: “Attacks shall be limited strictly to military objectives.” 
United Kingdom, The Manual of the Law of Armed Conflict, Ministry of Defence, 1 July 2004, § 5.4; see also §§ 12.21, 12.26 (air operations) and § 13.27 (maritime warfare).
In 1938, during a debate in the House of Commons, the UK Prime Minister Neville Chamberlain listed among rules of international law applicable to warfare on land, at sea and from the air the rule that “targets which are aimed at … must be legitimate military targets and must be capable of identification”. 
United Kingdom, House of Commons, Statement by the Prime Minister, Sir Neville Chamberlain, 21 June 1938, Hansard, Vol. 337, col. 937.
At the CDDH, the United Kingdom stated that it did not interpret the obligation in the first sentence of Article 47(2) of the draft Additional Protocol I (now Article 52(2))
as dealing with the question of incidental damage caused by attacks directed against military objectives. In its view, the purpose of the first sentence of the paragraph was to prohibit only such attacks as might be directed against non-military objectives. 
United Kingdom, Statement at the CDDH, Official Records, Vol. VI, CDDH/SR.41, 26 May 1977, p. 169, § 153.
It is reported that, during the War in the South Atlantic, both parties directed their hostile acts only against military objectives. 
Carlos Horacio Cerdá, El respeto del Derecho International Humanitario durante el Dessarollo del Conflicto Armado del Atlántico Sud, Report on the Practice of Argentina, 1997, Chapter 1.3.
In reply to questions in the House of Lords and House of Commons concerning military operations during the Gulf War in 1991, the UK Under-Secretary of State for Defence and the Minister of State for the Armed Forces stated that it was a policy of the allies to attack only military targets and facilities that sustained Iraq’s illegal occupation of Kuwait. 
United Kingdom, House of Lords, Statement by the Parliamentary Under-Secretary of State for Defence, 27 February 1991, Hansard, Vol. 526, Written Answers, col. 52; Statement by the Minister of State for the Armed Forces, 28 February 1991, Hansard, Vol. 186, Written Answers, col. 611.
A training video on IHL produced by the UK Ministry of Defence emphasizes that military operations must be directed only against military objectives. 
United Kingdom, Ministry of Defence, Training Video: The Geneva Conventions, 1986, Report on UK Practice, 1997, Chapter 1.3.
Upon ratification of the 1977 Additional Protocol I, the United Kingdom stated:
It is the understanding of the United Kingdom that … the first sentence of paragraph 2 [of Article 52] prohibits only such attacks as may be directed against non-military objectives; it does not deal with the question of collateral damage resulting from attacks directed against military objectives. 
United Kingdom, Reservations and declarations made upon ratification of the 1977 Additional Protocol I, 28 January 1998, § j.
In 2003, in reply to a written question in the House of Commons, the UK Secretary of State for Defence wrote:
The military campaign is crafted around the principle of minimum use of force. We attack only military objectives and combatants subject to the constraints of proportionality. If there is any expectation that harm will be caused to civilians, this must not be excessive when set against the direct and concrete military advantage anticipated from the attack. 
United Kingdom, House of Commons, Written answer by the Secretary of State for Defence, Hansard, 9 April 2003, Vol. 403, Written Answers, col. 297W.
The UK Government Strategy on the Protection of Civilians in Armed Conflict (2010) states: “IHL requires parties to a conflict to respect and protect civilians. In the conduct of military operations they must … only direct attacks against … military objectives.” 
United Kingdom, Foreign and Commonwealth Office, Government Strategy on the Protection of Civilians in Armed Conflict, March 2010, p. 4.
The UK Military Manual (1958) provides:
In defended towns and localities modern methods of bombardment will inevitably destroy many buildings and sites which are not military objectives. Such destruction, if incidental to the bombardment of military objectives is not unlawful. For example the bombardment of a war factory area may well destroy the houses of workers living in that area. If, on the other hand, bombardment is directed solely against a non-military objective, it is unlawful. 
United Kingdom, The Law of War on Land being Part III of the Manual of Military Law, The War Office, HMSO, 1958, § 288.
The UK LOAC Pamphlet (1981) provides that it is forbidden to attack “civilian objects as a deliberate method of warfare”. 
United Kingdom, The Law of Armed Conflict, D/DAT/13/35/66, Army Code 71130 (Revised 1981), Ministry of Defence, prepared under the Direction of The Chief of the General Staff, 1981, Section 4, p. 14, § 5(a).
The UK LOAC Manual (2004) provides: “The civilian population and individual civilians must not be attacked and must be protected against the dangers arising from military operations; civilian objects are similarly protected.” 
United Kingdom, The Manual of the Law of Armed Conflict, Ministry of Defence, 1 July 2004, § 12.26.
In its chapter on the conduct of hostilities, under the heading “Immunity of Civilian Objects”, the manual quotes from Article 52(1) of the 1977 Additional Protocol I: “Civilian objects shall not be the object of attack or of reprisals”. 
United Kingdom, The Manual of the Law of Armed Conflict, Ministry of Defence, 1 July 2004, § 5.24.
In a footnote to this quotation, the manual states: “The UK has reserved the right to take reprisal action against civilian objects in certain circumstances.” 
United Kingdom, The Manual of the Law of Armed Conflict, Ministry of Defence, 1 July 2004, § 5.24, footnote 100.
In its chapter on internal armed conflict, the manual states: “Civilian property must not be attacked.” 
United Kingdom, The Manual of the Law of Armed Conflict, Ministry of Defence, 1 July 2004, § 15.16.
Under the UK ICC Act (2001), it is a punishable offence to commit a war crime as defined in Article 8(2)(b)(ii) of the 1998 ICC Statute. 
United Kingdom, ICC Act, 2001, Sections 50(1) and 51(1) (England and Wales) and Section 58(1) (Northern Ireland).
At the CDDH, following the adoption of Article 47 of the draft Additional Protocol I (now Article 52), the United Kingdom stated that it “welcomed the reaffirmation, in paragraph 2, of the customary law rule that civilian objects must not be the direct object of attack”. 
United Kingdom, Statement at the CDDH, Official Records, Vol. VI, CDDH/SR.41, 26 May 1977, p. 169, § 153.
In 1996, during a debate in the UN Security Council on the situation in Lebanon, the United Kingdom stated that attacks directed at civilian targets must be put to an end. 
United Kingdom, Statement before the UN Security Council, UN Doc. S/PV.3653, 15 April 1996, p. 13.
In 2006, in a written answer to a question concerning, inter alia, “the implications under the Geneva Conventions of the targeting by Israel of civilian facilities and infrastructure in Gaza”, the UK Minister of State for the Middle East, Foreign and Commonwealth Office, stated: “We are opposed to the targeting of civilian facilities and call upon Israel to respect international law.” 
United Kingdom, House of Commons, Written answer by the Minister of State for the Middle East, Foreign and Commonwealth Office, Hansard, 10 July 2006, Vol. 448, Written Answers, col. 1522W.
The UK LOAC Manual (2004) states:
The term “civilian objects” would normally include cities, towns and villages as such but not military objectives within those places. It also includes … buildings and facilities used by civilians (so long as they do not fall within the definition of military objectives) such as housing estates and houses; apartment blocks and flats; factories and workshops producing goods of no military significance; offices, shops, markets and warehouses; farms and stables; schools, museums, places of worship and other similar buildings. 
United Kingdom, The Manual of the Law of Armed Conflict, Ministry of Defence, 1 July 2004, § 5.24.2.
In 1986, during a debate in the UN Security Council concerning the Iran–Iraq War, the United Kingdom voiced strong criticism of the recurrent bombing of civilian centres, qualifying it as a violation of international law under the Geneva Conventions. 
United Kingdom, Statement before the UN Security Council, UN Doc. S/PV.2666, 24 February 1986, pp. 21–22.
In 2007, in a written answer to several questions in the House of Commons concerning the situation in Darfur, Sudan, the UK Minister of State for Trade, Foreign and Commonwealth Office, wrote: “The Sudanese Government resumed bombing villages in Darfur last week, resulting in a number of civilian injuries and deaths. We condemn these attacks, which show little regard for human life.” 
United Kingdom, House of Commons, Written answer by the Minister of State for Trade, Foreign and Commonwealth Office, Hansard, 2 May 2007, Vol. 459, Written Answers, col. 1718W.
The UK LOAC Manual (2004) states: “The following classes of enemy aircraft are exempt from attack: … b. aircraft granted safe conduct by agreement between the parties to the conflict; and c. civil airliners.”  
United Kingdom, The Manual of the Law of Armed Conflict, Ministry of Defence, 1 July 2004, § 12.28.