Law of war

Purposes of the laws

It has often been commented that creating laws for something as inherently lawless as war seems like a lesson in absurdity. But based on the adherence to what amounted to customary international law by warring parties through the ages, it was felt that codifying laws of war would be beneficial.

Some of the central principles underlying laws of war are:

Wars should be limited to achieving the political goals that started the war (e.g., territorial control) and should not include unnecessary destruction.

Wars should be brought to an end as quickly as possible.

People and property that do not contribute to the war effort should be protected against unnecessary destruction and hardship.

To this end, laws of war are intended to mitigate the hardships of war by:

Protecting both combatants and non-combatants from unnecessary suffering.

Safeguarding certain fundamental human rights of persons who fall into the hands of the enemy, particularly prisoners of war, the wounded and sick, and civilians.

Facilitating the restoration of peace.

Principles of the laws of war

Military necessity, along with distinction, and proportionality, are three important principles of international humanitarian law governing the legal use of force in an armed conflict.

Military necessity is governed by several constraints: an attack or action must be intended to help in the defeat of the enemy; it must be an attack on a legitimate military objective, and the harm caused to civilians or civilian property must be proportional and not excessive in relation to the concrete and direct military advantage anticipated.

Distinction is a principle under international humanitarian law governing the legal use of force in an armed conflict, whereby belligerents must distinguish between combatants and civilians.

Proportionality is a principle under international humanitarian law governing the legal use of force in an armed conflict, whereby belligerents must make sure that the harm caused to civilians or civilian property is not excessive in relation to the concrete and direct military advantage expected by an attack on a legitimate military objective.

Example substantive laws of war

To fulfill the purposes noted above, the laws of war place substantive limits on the lawful exercise of a belligerent’s power. Generally speaking, the laws require that belligerents refrain from employing violence that is not reasonably necessary for military purposes and that belligerents conduct hostilities with regard for the principles of humanity and chivalry.

However, because the laws of war are based on consensus, the content and interpretation of such laws are extensive, contested, and ever-changing. The following are particular examples of some of the substance of the laws of war, as those laws are interpreted today.

Declaration of war

Section III of the Hague Convention of 1907 required hostilities to be preceded by a reasoned declaration of war or by an ultimatum with a conditional declaration of war.

Some treaties, notably the United Nations Charter (1945) Article 2, and other articles in the Charter, seek to curtail the right of member states to declare war; as does the older Kellogg–Briand Pact of 1928 for those nations who ratified it.

Lawful conduct of belligerent actors

Modern laws of war regarding conduct during war (jus in bello), such as the 1949 Geneva Conventions, provide that it is unlawful for belligerents to engage in combat without meeting certain requirements, such as wearing distinctive uniform or other distinctive signs visible at a distance, carrying weapons openly, and conducting operations in accordance with the laws and customs of war. Impersonating enemy combatants by wearing the enemy’s uniform is allowed, though fighting in that uniform is unlawful perfidy, as is the taking of hostages.

Combatants also must be commanded by a responsible officer. That is, a commander can be held liable in a court of law for the improper actions of his or her subordinates. There is an exception to this if the war came on so suddenly that there was no time to organize a resistance, e.g. as a result of a foreign occupation.

Persons parachuting from an aircraft in distress

Modern laws of war, specifically within Protocol I additional to the 1949 Geneva Conventions, prohibits attacking persons parachuting from an aircraft in distress regardless of what territory they are over. Once they land in territory controlled by the enemy, they must be given an opportunity to surrender before being attacked unless it is apparent that they are engaging in a hostile act or attempting to escape. This prohibition does not apply to the dropping of airborne troops, special forces, commandos, spies, saboteurs, liaison officers, and intelligence agents. Thus, such personnel descending by parachutes are legitimate targets and, therefore, may be attacked, even if their aircraft is in distress.

Red Cross, Red Crescent, Magen David Adom, and the white flag

Modern laws of war, such as the 1949 Geneva Conventions, also include prohibitions on attacking doctors, ambulances or hospital ships displaying a Red Cross, a Red Crescent, Magen David Adom, The Red Crystal, or other emblem related to the International Red Cross and Red Crescent Movement. It is also prohibited to fire at a person or vehicle bearing a white flag, since that indicates an intent to surrender or a desire to communicate.

In either case, persons protected by the Red Cross/Crescent/Star or white flag are expected to maintain neutrality, and may not engage in warlike acts. In fact, engaging in war activities under a protected symbol is itself a violation of the laws of war known as perfidy. Failure to follow these requirements can result in the loss of protected status and make the individual violating the requirements a lawful target.

Applicability to states and individuals

The law of war is binding not only upon States as such but also upon individuals and, in particular, the members of their armed forces. Parties are bound by the laws of war to the extent that such compliance does not interfere with achieving legitimate military goals. For example, they are obliged to make every effort to avoid damaging people and property not involved in combat or the war effort, but they are not guilty of a war crime if a bomb mistakenly or incidentally hits a residential area.

By the same token, combatants that intentionally use protected people or property as human shields or camouflage are guilty of violations of the laws of war and are responsible for damage to those that should be protected. The use of contracted combatants in warfare has been an especially tricky situation for the laws of war. Some scholars claim that private security contractors appear so similar to state forces that it is unclear if acts of war are taking place by private or public agents. International law has yet to come to a consensus on this issue.

Remedies for violations

During conflict, punishment for violating the laws of war may consist of a specific, deliberate and limited violation of the laws of war in reprisal.

After a conflict has ended, persons who have committed or ordered any breach of the laws of war, especially atrocities, may be held individually accountable for war crimes through process of law. Also, nations which signed the Geneva Conventions are required to search for, then try and punish, anyone who has committed or ordered certain "grave breaches" of the laws of war. (Third Geneva Convention, Article 129 and Article 130.)

Combatants who break specific provisions of the laws of war are termed unlawful combatants. Unlawful combatants who have been captured may lose the status and protections that would otherwise be afforded to them as prisoners of war, but only after a "competent tribunal" has determined that they are not eligible for POW status (e.g., Third Geneva Convention, Article 5.) At that point, an unlawful combatant may be interrogated, tried, imprisoned, and even executed for their violation of the laws of war pursuant to the domestic law of their captor, but they are still entitled to certain additional protections, including that they be "treated with humanity and, in case of trial, shall not be deprived of the rights of fair and regular trial." (Fourth Geneva Convention Article 5.)

For example, in 1976, foreign soldiers fighting for the National Liberation Front of Angola (FNLA) were captured by the People's Movement for the Liberation of Angola (MPLA) during the Angolan Civil War in 1975. In the Luanda Trial, after "a regularly constituted court" found them guilty of being unlawful mercenaries, three Britons and an American were shot by a firing squad on July 10, 1976. Nine others were imprisoned for terms of 16 to 30 years.

International treaties on the laws of war

List of declarations, conventions, treaties and judgments, and on the laws of war:

1856 Paris Declaration Respecting Maritime Law abolished privateering.

1864 Geneva Convention for the Amelioration of the Condition of the Wounded and Sick in Armed Forces in the Field.

1868 St. Petersburg Declaration Renouncing the Use, in Time of War, of Explosive projectiles Under 400 grams Weight.

1874 Project of an International Declaration concerning the Laws and Customs of War (Brussels Declaration). Signed in Brussels 27 August. This agreement never entered into force, but formed part of the basis for the codification of the laws of war at the 1899 Hague Peace Conference.

1880 Manual of the Laws and Customs of War at Oxford. At its session in Geneva in 1874 the Institute of International Law appointed a committee to study the Brussels Declaration of the same year and to submit to the Institute its opinion and supplementary proposals on the subject. The work of the Institute led to the adoption of the Manual in 1880 and it went on to form part of the basis for the codification of the laws of war at the 1899 Hague Peace Conference.

1899 Hague Conventions consisted of three main sections and three additional declarations:

I – Pacific Settlement of International Disputes

II – Laws and Customs of War on Land

III – Adaptation to Maritime Warfare of Principles of Geneva Convention of 1864

Declaration I – On the Launching of Projectiles and Explosives from Balloons

Declaration II – On the Use of Projectiles the Object of Which is the Diffusion of Asphyxiating or Deleterious Gases

Declaration III – On the Use of Bullets Which Expand or Flatten Easily in the Human Body

1907 Hague Conventions had thirteen sections, of which twelve were ratified and entered into force, and two declarations:

I – The Pacific Settlement of International Disputes

II – The Limitation of Employment of Force for Recovery of Contract Debts

III – The Opening of Hostilities

IV – The Laws and Customs of War on Land

V – The Rights and Duties of Neutral Powers and Persons in Case of War on Land

VI – The Status of Enemy Merchant Ships at the Outbreak of Hostilities

VII – The Conversion of Merchant Ships into War-ships

VIII – The Laying of Automatic Submarine Contact Mines

IX – Bombardment by Naval Forces in Time of War

X – Adaptation to Maritime War of the Principles of the Geneva Convention

XI – Certain Restrictions with Regard to the Exercise of the Right of Capture in Naval War

XII – The Creation of an International Prize Court [Not Ratified]*

XIII – The Rights and Duties of Neutral Powers in Naval War

Declaration I – extending Declaration II from the 1899 Conference to other types of aircraft

Declaration II – on the obligatory arbitration

1909 London Declaration concerning the Laws of Naval War largely reiterated existing law, although it showed greater regard to the rights of neutral entities. Never went into effect.

1922 The Washington Naval Treaty, also known as the Five-Power Treaty (6 February).

1923 Hague Draft Rules of Aerial Warfare. Never adopted in a legally binding form.

1925 Geneva protocol for the Prohibition of the Use in War of Asphyxiating, Poisonous or Other Gases, and of Bacteriological Methods of Warfare.

1927–1930 Greco-German arbitration tribunal.

1928 Kellogg-Briand Pact (also known as the Pact of Paris).

1929 Geneva Convention, Relative to the treatment of prisoners of war.

1929 Geneva Convention on the amelioration of the condition of the wounded and sick.

1930 Treaty for the Limitation and Reduction of Naval Armament (22 April).

1935 Roerich Pact.

1936 Second London Naval Treaty (25 March).

1938 Amsterdam Draft Convention for the Protection of Civilian Populations Against New Engines of War. This convention was never ratified.

1938 League of Nations declaration for the "Protection of Civilian Populations Against Bombing From the Air in Case of War."

1945 United Nations Charter (entered into force on October 24, 1945).

1946 Judgment of the International Military Tribunal at Nuremberg.

1947 Nuremberg Principles formulated under UN General Assembly Resolution 177 21 November 1947.

1948 United Nations Convention on the Prevention and Punishment of the Crime of Genocide.

1949 Geneva Convention I for the Amelioration of the Condition of the Wounded and Sick in Armed Forces in the Field.

1949 Geneva Convention II for the Amelioration of the Condition of Wounded, Sick and Shipwrecked Members of Armed Forces at Sea.

1949 Geneva Convention III Relative to the Treatment of Prisoners of War.

1949 Geneva Convention IV Relative to the Protection of Civilian Persons in Time of War.

1954 Hague Convention for the Protection of Cultural Property in the Event of Armed Conflict.

1971 Zagreb Resolution of the Institute of International Law on Conditions of Application of Humanitarian Rules of Armed Conflict to Hostilities in which the United Nations Forces May be Engaged.

1974 United Nations Declaration on the Protection of Women and Children in Emergency and Armed Conflict.

1977 United Nations Convention on the Prohibition of Military or Any Other Hostile Use of Environmental Modification Techniques.

1977 Geneva Protocol I Additional to the Geneva Conventions of 12 August 1949, and Relating to the Protection of Victims of International Armed Conflicts.

1977 Geneva Protocol II Additional to the Geneva Conventions of 12 August 1949, and Relating to the Protection of Victims of Non-International Armed Conflicts.

1978 Red Cross Fundamental Rules of International Humanitarian Law Applicable in Armed Conflicts.

1980 United Nations Convention on Prohibitions or Restrictions on the Use of Certain Conventional Weapons Which May be Deemed to be Excessively Injurious or to Have Indiscriminate Effects (CCW).

1980 Protocol I on Non-Detectable Fragments.

1980 Protocol II on Prohibitions or Restrictions on the Use of Mines, Booby-Traps and Other Devices.

1980 Protocol III on Prohibitions or Restrictions on the Use of Incendiary Weapons.

1995 Protocol IV on Blinding Laser Weapons.

1996 Amended Protocol II on Prohibitions or Restrictions on the Use of Mines, Booby-Traps and Other Devices.

Protocol on Explosive Remnants of War (Protocol V to the 1980 Convention), 28 November 2003, entered into force on 12 November 2006.

1994 San Remo Manual on International Law Applicable to Armed Conflicts at Sea.

1994 ICRC/UNGA Guidelines for Military Manuals and Instructions on the Protection of the Environment in Time of Armed Conflict.

1994 UN Convention on the Safety of United Nations and Associated Personnel.

1996 The International Court of Justice advisory opinion on the Legality of the Threat or Use of Nuclear Weapons.

1997 Ottawa Treaty - Convention on the Prohibition of the Use, Stockpiling, Production and Transfer of Anti-Personnel Mines and on their Destruction.

1998 Rome Statute of the International Criminal Court (entered into force 1 July 2002).

2000 Optional Protocol on the Involvement of Children in Armed Conflict (entered into force 12 February 2002).

2005 Geneva Protocol III Additional to the Geneva Conventions of 12 August 1949, and Relating to the Adoption of an Additional Distinctive Emblem.

2008 Convention on Cluster Munitions (entered into force 1 August 2010).