The Practical Guide to Humanitarian Law

« Calling things by the wrong name adds to the affliction of the world. » Albert Camus.



International law provides no clear definition for the term terrorism . It has political and ideological connotations. One man’s terrorist is another man’s freedom fighter.

Despite attempts of the United Nations, States have not yet agreed upon a definition of terrorism. Nonetheless, we will keep in mind the definitions proposed by the United Nations and the European Union.

Attempts of Definition by the United Nations

The International Convention for the Suppression of the Financing of Terrorism, signed on 9 December 1999, defines terrorism in its Article 2.1.b as “any . . . act intended to cause death or serious bodily injury to a civilian, or to any other person not taking an active part in the hostilities in a situation of armed conflict, when the purpose of such act, by its nature or context, is to intimidate a population, or to compel a government or an international organization to do or to abstain from doing any act.”

The United Nations Security Council, it its resolution 1566 of October 2004, elaborates this definition, stating that terrorists acts are “criminal acts, including against civilians, committed with the intent to cause death or serious bodily injury, or taking of hostages, with the purpose to provoke a state of terror in the general public or in a group of persons or particular persons, intimidate a population or compel a government or an international organization to do or to abstain from doing any act.” The Security Council recalls that such acts are “under no circumstances justifiable by considerations of a political, philosophical, ideological, racial, ethnic, religious or other similar nature.” The UN General Assembly reaffirmed this definition in January 2006 (Resolution 60/43), defining terrorist acts as “criminal acts intended or calculated to provoke a state of terror in the general public, a group of persons or particular persons for political purposes.”

In 2004, the UN set up a High-Level Panel on Threats, Challenges, and Change. In their report to the UN Secretary General in December 2004, titled “A More Secure World, Our Shared Responsibility,” the experts proposed to define terrorism as “any action . . . that is intended to cause death or serious bodily harm to civilians or non-combatants, when the purpose of such an act, by its nature or context, is to intimidate a population, or to compel a Government or an international organization to do or to abstain from doing any act” (para. 164(d), p. 49). This definition is sensibly the same as the one proposed by the UN Security Council, though it adds the notions of civilians or “non-combatants” as potential targets of terrorist attacks.

Attempts of Definition by the European Union

While the 1977 European Convention on the Suppression of Terrorism does not provide a clear definition of terrorism, the Council Framework Decision of 13 June 2002 on combating terrorism proposes an exhaustive definition:

Article 1 states that terrorist offenses are

offences under national law, which, given their nature or context, may seriously damage a country or an international organisation and committed with the aim of:

  • seriously intimidating a population, or

  • unduly compelling a Government or international organisation to perform or abstain from performing any act, or

  • seriously destabilising or destroying the fundamental political, constitutional, economic or social structures of a country or an international organisation, shall be deemed to be terrorist offences:

    1. attacks upon a person’s life which may cause death;
    2. attacks upon the physical integrity of a person;
    3. kidnapping or hostage taking;
    4. causing extensive destruction to a Government or public facility, a transport system, an infrastructure facility, including an information system, a fixed platform located on the continental shelf, a public place or private property likely to endanger human life or result in major economic loss;
    5. seizure of aircraft, ships or other means of public or goods transport;
    6. manufacture, possession, acquisition, transport, supply or use of weapons, explosives or of nuclear, biological or chemical weapons, as well as research into, and development of, biological and chemical weapons
    7. release of dangerous substances, or causing fires, floods or explosions the effect of which is to endanger human life;
    8. interfering with or disrupting the supply of water, power or any other fundamental natural resource the effect of which is to endanger human life;
    9. threatening to commit any of the acts listed in (a) to (h).

Because this definition is close to that of a war crime, the Council Framework decision specifies that “actions by armed forces during periods of armed conflict . . . and actions by the armed forces of a State in the exercise of their official duties are not governed by this Framework Decision” (Introduction, para. 11), thus excluding from the scope of the Convention the measures of protection taken by States in situations of internal disturbances and armed conflict.

In May 2005, the Council of Europe adopted the Convention on the Prevention of Terrorism, which takes up the above definitions: “acts of terrorism have the purpose by their nature or context to seriously intimidate a population or unduly compel a government or an international organisation to perform or abstain from performing any act or seriously destabilise or destroy the fundamental political, constitutional, economic or social structures of a country or an international organisation” (Introduction). As in the Council Framework Decision, it is stated in Article 26.5 that official armies are not affected by this agreement.

Some common elements emerge from these definitions: the ideological nature of the terrorist act; the fact that it is directed against a population that does not participate in hostilities in the context of an armed conflict; the fact that the mere threat to commit a terrorist act is sufficient to define it as such; and finally, the fact that it aims at undermining a government or an international organization, notably through the destruction of its infrastructures. This last element echoes with the attacks in Afghanistan and Iraq against UN infrastructures, including the murderous attack against the UN headquarters in Baghdad in August 2003.

Means to Fight Terrorism

It is important to make a clear distinction between terrorist acts and activities and the use of terror as a method of warfare in the context of an armed conflict carried out by States or non-states belligerents who may not have been formally recognized by national authorities (such as guerrilla and other resistance movements). Where terror is used within an armed conflict, international humanitarian law applies to all parties concerned; it sets out mandatory rules regarding methods of warfare and the use of force by State and non-state actors, treatment of combatants and civilians, and penalties for crimes. Humanitarian law applies to military occupation.

What governments often call acts of “terrorism” may in fact be non-international armed conflicts if acts of violence are organized in a continuous and concerted way and from areas of territory that are—even partly—not under the control of the national authorities. In such situations, authorities must respect humanitarian law; it is not enough to respect national law applicable in situations of emergency and to strengthen the authority of the police force (APII Art. 1). ▸ International humanitarian lawNon-international armed conflictTerror

Where the use of terror is not part of an armed conflict the State generally responds by increasing the police force’s authority and activities in order to protect public order. A State may also temporarily limit certain human rights and freedoms. In all cases, Common Article 3 to the four Geneva Conventions, together with non-derogable rules defined by international human rights conventions, continue to apply as they have the same content and part of Common Article 3 are said to apply at all times. ▸ Fundamental guaranteesHuman rightsOccupied territoryPublic order

The effort to reach a universal consensus in condemning terrorism has grown in recent years, with the UN and regional organizations adopting declarations suggesting measures to combat terrorism. As early as 1992, the UN Security Council adopted a resolution stating that international terrorism is a threat to international peace and security (Resolution S/RES/748). This has been confirmed by several resolutions adopted after 11 September 2001, according to which “terrorism constitutes one of the most serious threats to international peace and security in the twenty-first century” (S/RES/1377 [2001]). The Security Council acknowledges that, in case of terrorist attack, States may use armed forces as part of their right to individual or collective self-defense in accordance with the UN Charter (S/RES /1368 [2001]). ▸ Self-defense

The Security Council insists that reinforcement of the rule of law and development of cooperation between States is a precondition to the fight against terrorism. Most of the texts aim at emphasizing States’ responsibilities to reinforce their control of and limit any tacit consent to the activities of these groups. The Security Council, acting under Chapter VII of the UN Charter, adopted a special resolution that all States must comply with regarding the prevention and suppression of financing of terrorist acts and the passing of adequate legislation to allow effective control over their territory and prevent the hostile use of their territory toward other States. The resolution requires increased police and judicial cooperation, particularly with regard to the arrest of suspects (S/RES/1373[2001]). This resolution, passed on 28 September 2001, established a Committee of Sanction to support States’ implementation of the resolution. ▸ Sanctions Committee

With regard to the 11 September 2001 attacks against the United States of America, attributed to Al Qaeda, the refusal of the Afghan government to cooperate in the arrest of members of the Bin Laden network operating on Afghan soil was considered as active support for terrorist activities. The Afghan government was held accountable as a result, justifying the military attack launched on 7 October 2001.

During the 2005 World Summit, the UN General Assembly recalled that terrorism must be condemned in all its forms and manifestations and decided to elaborate an international strategy to combat terrorism. This strategy, called the UN Global Counter-Terrorism Strategy, was adopted by the GA on 8 September 2006 (Resolution 60/288). The goal of the Strategy is to prevent and combat terrorism at national, regional, and international levels through the adoption of practical measures. In its Resolution, the GA proposes, inter alia, to strengthen UN capacities in areas such as conflict prevention and peacekeeping; to encourage initiatives that promote dialogue, tolerance, and understanding among civilizations; to adopt measures that prohibit by law the incitement to commit terrorist acts; to encourage a better cooperation among States through information sharing; to adopt measures to protect the victims of terrorism; and to encourage the creation of an international center to combat terrorism. On this basis, the International Centre for Counter-Terrorism (ICCT) was created on 31 May 2010 in The Hague, Netherlands. This is an independent knowledge center composed of academic and governmental experts who focus on information creation, collation, and dissemination pertaining to the preventative and international legal aspects of counterterrorism.

In order to study the links between the promotion and protection of human rights and the counterterrorism strategy, a Special Rapporteur was appointed in April 2005 by the Commission on Human Rights. The mandate of the Special Rapporteur on the promotion and protection of human rights and fundamental freedoms while countering terrorism was last extended by the Human Rights Council for a period of three years in October 2010. As of August 2011, this is Mr. Ben Emmerson, from the United Kingdom.

Special Rapporteur


In times of peace, various international conventions that regulate mutual assistance in criminal matters address some of the measures to be taken. Those specifically related to terrorism include the following:

  • European Convention on the Suppression of Terrorism of 27 January 1977, adopted under the aegis of the Council of Europe and entered into force on 4 August 1978 (forty-six States Parties as of June 2015).
  • Council of Europe Convention on the Prevention of Terrorism, adopted in May 2005 and entered into force on 1 June 2007 (currently, thirty-three States Parties).
  • Convention to Prevent and Punish the Acts of Terrorism Taking the Form of Crimes against Persons and Related Extortion That Are of International Significance, adopted under the aegis of the Organization of American States on 2 February 1971 (it enters into force for each State as it ratifies the convention). As of April 2013, it had eighteen States Parties.
  • International Convention for the Suppression of Terrorist Bombings, adopted by the General Assembly of the United Nations on 15 December 1997 and entered into force on 23 May 2001. As of June 2015, it had 168 States Parties.
  • International Convention for the Suppression of the Financing of Terrorism, adopted by the General Assembly of the United Nations on 9 December 1999 and entered into force on 10 April 2002. As of June 2015, it had 186 States Parties.
  • International Convention for the Suppression of Acts of Nuclear Terrorism, adopted by the General Assembly of the United Nations on 13 April 2005 and entered into force on 7 July 2007). As of June 2015, it had 99 States Parties.
  • Organization of the African Union Convention on the Prevention and Combating of Terrorism, adopted in Algiers, Algeria, on 14 July 1999 (it entered into force on 6 December 2002). As of June 2015, it had forty-one States Parties.
  • Arab Convention for the Suppression of Terrorism, adopted in Cairo by the League of Arab States on 22 April 1998 and entered into force on 7 May 1999.

In times of conflict, humanitarian law prohibits terror as a method of warfare, such as attacks against the civilian population, civilian objects, and property.

International humanitarian law also prohibits any acts or threats the primary purpose of which is to spread terror among the civilian population. This applies to both international and internal armed conflicts (API Art. 51, APII Art. 13). No protected person may be punished for an offense he or she has not personally committed. Collective penalties and all measures of intimidation or of terrorism are prohibited (GCIV Art. 33).

The following acts are prohibited at all time and in all places: violence to the life, health, and physical or mental well-being of persons; collective punishments; taking of hostages; acts of terrorism (APII Art. 4.2.d).

International humanitarian law takes into account the specificity of guerrillas’ methods of warfare to ensure that such acts are not considered as mere terrorism, therefore preventing the law of armed conflict from applying. On the other hand, humanitarian law provides minimal opportunity for members of these groups to be afforded combatant status and associated protections—including prisoner-of-war protection (API Art. 44). According to it, armed force must be used within a hierarchically organized framework, under responsible command able to enforce humanitarian law. Further, combatants must carry arms openly when engaged in hostilities.

In times of armed conflict, “terrorist” is not a specific legal category under humanitarian law. Geneva Conventions and Additional Protocols only allow for a distinction between civilians and combatants—or between those who take part in hostilities and those who do not or who have since laid down arms. Further, humanitarian law prohibits methods of warfare that are primarily designed to spread terror among the civilian population. Persons who employ such methods commit a crime yet remain members of the civilian population. Therefore, authorities in charge of such persons must indict and prosecute them according to the rule of law.

If such persons act as member of a non-state armed group or with the support or on behalf of a State authority in the framework of an armed conflict, they enter into the category of combatants or into the one of civilians directly participating in hostilities. A combatant who resorts to such practices can be arrested, detained, and prosecuted for his or her criminal activities. If so, guarantees in regard to detention, interrogation, and fair trial provided by IHL must be respected. Terrorists do not have any specific legal status under humanitarian law. Besides, jurisprudence of domestic courts interpreting international humanitarian law has shown that, under IHL, the so-called global war on terror does not constitute a third type of conflict involving “unlawful combatants” who would escape any rules provided for international and non-international armed conflicts. This was confirmed by several judgments pronounced by the United States and the Israel Supreme Courts, which denied, on this issue, the doctrine developed by governmental authorities and jurists in the context of their management of the terrorist threat.

AttacksCombatantJudicial guaranteesMethods (and means) of warfareMutual assistance in judicial mattersPrisoners of warResistance movementsSecurity Council of the UNTerrorWar crimes/Crimes against humanity


  1. Israel Supreme Court

In a judgment pronounced on 11 December 2005 ( Supreme Court Sitting as the High Court of Justice, the Public Committee against Torture in Israel , HCJ 759/02), the Israel Supreme Court recognized the following facts:

  • Terrorists do not belong to a third category of “unlawful” combatants: The Court affirmed that the notions of combatants and civilians were mutually exclusive. There is no other category, such as that of “unlawful” combatants. Those persons, who sometimes do not enjoy the combatant status, remain civilians, even if they lose part of their protection because of their direct participation in hostilities. “That definition [of combatant] is ‘negative’ in nature. It defines the concept of ‘civilian’ as the opposite of ‘combatant’. It thus views unlawful combatants—who, as we have seen, are not ‘combatants’—as civilians. Does that mean that the unlawful combatants are entitled to the same protection to which civilians who are not unlawful combatants are entitled? The answer is, no. . . . An unlawful combatant is not a combatant, rather a ‘civilian’. However, he is a civilian who is not protected from attack as long as he is taking a direct part in the hostilities” (para. 26).

The Court held that terrorists who participate directly in the hostilities do not cease to be civilians but lose the civilian status because of their acts. Besides, they do not enjoy the rights granted to combatants: “True, terrorists participating in hostilities do not cease to be civilians, but by their acts they deny themselves the aspect of their civilian status which grants them protection from military attack. Nor do they enjoy the rights of combatants, e.g. the status of prisoners of war” (para. 31).

  • The war on terror does not constitute a third category of armed conflict:

In the oral and written arguments before us, the State raised the possibility that we recognize the existence of a third legal category [of conflict]. According to that approach, the conflict between a State and a terrorist organization and its members constitutes a separate category of armed conflict. The laws of international armed conflict are not to be applied to this conflict, as those laws deal with conflicts between sovereign States. Nor should this conflict be seen as an armed conflict which is non-international, since it is not limited to the territory of the State alone. . . . In international law, a third category should be recognized, of an armed conflict between a State (or States) and terrorist organizations. In the framework of this third category, “special laws of combat, which fit this special situation” will be formulated. . . . We shall take no stance regarding the question whether it is desirable to recognize this third category. The question before us is not one of desirable law, rather one of existing law. In our opinion, as far as existing law goes, the data before us are not sufficient to recognize this third category. That is the case according to the current state of international law, both international treaty law and customary international law. . . . It is difficult for us to see how a third category can be recognized in the framework of The Hague and Geneva Conventions. It does not appear to us that we were presented with data sufficient to allow us to say, at the present time, that such a third category has been recognized in customary international law.” (paras. 27, 28)

  1. Supreme Court of the United States
  • The crime of aiding and abetting terrorist organizations: On this subject, jurisprudence evolves slowly. Several decisions from U.S. tribunals had given a very broad interpretation of the crime of aiding and abetting terrorist activities. The most controversial part of those decisions lies in the material character of the crime, without requiring the proof of specific intent or the knowledge of the criminal character of the activities. The extensive definition of this offense could lead to the criminalization of certain actors or actions of a humanitarian character, on the grounds that they constitute material support to terrorist activities. This criminalization could also apply to the delivery of medical care to patients accused of supporting or belonging to terrorist organizations. (On this subject, see U.S. Supreme Court, Holder v. Humanitarian Law Project , no. 08/1498, 21 June 2010.)
  1. Other Courts

In 2007 the Federal Court of Australia delineated the notion of guilt of association with regard to terrorist activities. In Haneef v. Ministry of Immigration and Citizenship (FCA 1273, 21 August 2007), the Court held that, for the law to apply, the “association” must itself be of criminal nature rather than of a family or an innocent nature.

International jurisprudence began to control certain elements relating to the establishment of lists of terrorist organizations by States at the national, regional, or international level. In this regard, the European Union Court of Justice held in 2006 that individuals associated to an organization classified as “terrorist” had the right to know the reason of their inscription on this list, had the right to be heard and benefit from judicial protection ( Organisation des Modjahedines du peuple d’Iran v. Council of the European Union, Supported by United Kingdom of Great Britain and Northern Ireland , Judgment of the Court of First Instance [Second Chamber], 12 December 2006).


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