"Laws are silent amidst the clash of arms." - Cicero
In other words, war by its very nature is beyond the law. Wars break out when
the rule of law breaks down, so there are no longer any rules.
The history of the law of international armed conflict shows that the field of
application of this legal regime has been progressively extended as treaty law
developed. Whereas a narrow formalistic concept of war was predominant
initially, the reform of the system with the revision of the Geneva Conventions
in 1949 gave precedence to a broader approach, based on the more objective
concept of armed conflict.
Moreover, that extension was subsequently taken up with the adoption of
Additional Protocol I in 1977. That instrument added another type of conflict to
the field of the law of international armed conflict, that of wars of national
liberation. This legal regime also comprises a specific body of rules whose
field of application is determined based on an autonomous concept, that of
The States parties to the 1949 Geneva Conventions have entrusted the ICRC,
through the Statutes of the International Red Cross and Red Crescent Movement,
"to work for the understanding and dissemination of knowledge of international
humanitarian law applicable in armed conflicts and to prepare any development
It is on this basis that the ICRC takes this opportunity to present the
prevailing legal opinion on the definition of "international armed conflict" and
"non-international armed conflict" under International Humanitarian Law, the
branch of international law which governs armed conflict.
International humanitarian law distinguishes two types of armed conflicts,
- International armed conflicts, opposing two or more States, and
- Non-international armed conflicts, between governmental forces and
nongovernmental armed groups, or between such groups only.
International Humanitarian treaty law also establishes a distinction between
non-international armed conflicts in the meaning of common Article 3 of the
Geneva Conventions of 1949 and non-international armed conflicts falling within
the definition provided in Article 1 of Additional Protocol II.
Legally speaking, no other type of armed conflict exists. It is nevertheless
important to underline that a situation can evolve from one type of armed
conflict to another, depending on the facts prevailing at a certain moment.
International Armed Conflicts
The international armed conflict has been defined in Common Article 2 to the
Geneva Conventions of 1949 which states that:
"In addition to the provisions which shall be implemented in peacetime, the
present Convention shall apply to all cases of declared war or of any other
armed conflict which may arise between two or more of the High Contracting
Parties, even if the state of war is not recognized by one of them.
The Convention shall also apply to all cases of partial or total occupation of
the territory of a High Contracting Party, even if the said occupation meets
with no armed resistance."
According to this provision, IACs are those which oppose "High Contracting
Parties", meaning States. An IAC occurs when one or more States have recourse to
armed force against another State, regardless of the reasons or the intensity of
this confrontation. Relevant rules of IHL may be applicable even in the absence
of open hostilities.
The Commentary of the Geneva Conventions of 1949 confirms that "any difference
arising between two States and leading to the intervention of armed forces is an
armed conflict within the meaning of Article 2, even if one of the Parties
denies the existence of a state of war. It makes no difference how long the
conflict lasts, or how much slaughter takes place."
Interpretation of term:
The International Criminal Tribunal for the former Yugoslavia (ICTY) proposed a
general definition of international armed conflict. In the Tadic case
the Tribunal stated that:
"An armed conflict exists whenever there is a resort to armed force between
States". This definition has been adopted by other international bodies since
According to D. Schindler:
"The existence of an armed conflict within the meaning of Article 2 common to
the Geneva Conventions can always be assumed when parts of the armed forces of
two States clash with each other. […] Any kind of use of arms between two States
brings the Conventions into effect".
H.P. Gasser explains that "any use of armed force by one State against the
territory of another, triggers the applicability of the Geneva Conventions
between the two States. […] It is also of no concern whether or not the party
attacked resists. […] As soon as the armed forces of one State find themselves
with wounded or surrendering members of the armed forces or civilians of another
State on their hands, as soon as they detain prisoners or have actual control
over a part of the territory of the enemy State, then they must comply with the
Non-International Armed Conflict
Two main legal sources must be examined to determine what a Non-International
Armed Conflict under international humanitarian law is:
- Common Article 3 to the Geneva Conventions of 1949 –
Common Article 3 applies to "armed conflicts not of an international
character occurring in the territory of one of the High Contracting
Parties". These include armed conflicts in which one or more
non-governmental armed groups are involved. Depending on the situation,
hostilities may occur between governmental armed forces and non-governmental
armed groups or between such groups only.
As the four Geneva Conventions have universally been ratified now, the
requirement that the armed conflict must occur "in the territory of one of
the High Contracting Parties" has lost its importance in practice. Indeed,
any armed conflict between governmental armed forces and armed groups or
between such groups cannot but take place on the territory of one of the
Parties to the Convention.
To distinguish an armed conflict, in the meaning of common Article 3, from
less serious forms of violence, such as internal disturbances and tensions,
riots, or acts of banditry, the situation must reach a certain threshold of
confrontation. It has been generally accepted that the lower threshold found
in Article 1(2) of Additional Protocol II, which excludes internal
disturbances and tensions from the definition of Non-International Armed
Conflict, also applies to common Article 3.
Two criteria are usually used in this regard:
- First, the hostilities must reach a minimum level of intensity. This may
be the case, for example, when the hostilities are collective or when the
government is obliged to use military force against the insurgents, instead
of mere police forces.
- Second, non-governmental groups involved in the conflict must be
considered as "parties to the conflict", meaning that they possess organized
armed forces. This means for example that these forces have to be under a
certain command structure and have the capacity to sustain military
- Article 1 of Additional Protocol II:
A more restrictive definition of Non-International Armed Conflict was adopted
for the specific purpose of Additional Protocol II. This instrument applies to
armed conflicts "which take place in the territory of a High Contracting Party
between its armed forces and dissident armed forces or other organized armed
groups which, under responsible command, exercise such control over a part of
its territory as to enable them to carry out sustained and concerted military
operations and to implement this Protocol."
This definition is narrower than the notion of Non-International Armed Conflict
under common Article 3 in two aspects.
- Firstly, it introduces a requirement of territorial control, by
providing that non-governmental parties must exercise such territorial
control "as to enable them to carry out sustained and concerted military
operations and to implement this Protocol".
- Secondly, Additional Protocol II expressly applies only to armed
conflicts between State armed forces and dissident armed forces or other
organized armed groups. Contrary to common Article 3, the Protocol does not
apply to armed conflicts occurring only between non-State armed groups.
In this context, it must be reminded that Additional Protocol II "develops and
supplements" common Article 3 "without modifying its existing conditions of
application." This means that this restrictive definition is relevant for
the application of Protocol II only, but does not extend to the law of NIAC in
general. The Statute of the International Criminal Court in its article 8,
paragraph 2 (f), confirms the existence of a definition of a non-international
armed conflict not fulfilling the criteria of Protocol II.
Interpretation of the term:
Case law has brought important elements for a definition of an armed conflict,
in particular regarding the non-international armed conflicts in the meanings of
common Article 3 which are not expressly defined in the Conventions concerned.
Several recognized authors also commented very clearly on what should be
considered as a non-international armed conflict. Their comments are relevant in
the first place to the conflicts which do not fulfill the strict criteria
foreseen in Additional Protocol II and provide useful elements to ensure the
application of the guarantees provided in common article 3 to the Geneva
Conventions of 1949.
According to H.P. Gasser, it is generally admitted that:
conflicts are armed confrontations that take place within the territory of a
State between the governments on the one hand and armed insurgent groups on the
other hand. […] Another case is the crumbling of all government authority in the
country, as a result of which various groups fight each other in the power
D. Schindler also proposes a detailed definition:
"The hostilities have to be
conducted by a force of arms and exhibit such intensity that, as a rule, the
government is compelled to employ its armed forces against the insurgents
instead of mere police forces. Secondly, as to the insurgents, the hostilities
are meant to be collective, [i.e] they have to be carried out not only by single
groups. Besides, the insurgents have to exhibit a minimum amount of
organization. Their armed forces should be under a responsible command and be
capable of meeting minimal humanitarian requirements."
Additionally, Articles 1 and 7 of the Statute of the International Criminal
Tribunal for Rwanda extend the jurisdiction of that tribunal called to enforce,
inter alia, the law of non-international armed conflicts, to the neighboring
countries. This confirms that even a conflict spreading across borders remains a
non-international armed conflict. In conclusion, 'internal conflicts are
distinguished from international armed conflicts by the parties involved rather
than by the territorial scope of the conflict.'
Application of International law in matters concerning Non-International Armed
In a non-international armed conflict, each party is bound to apply, as a
minimum, the fundamental humanitarian provisions of international law contained
in Article 3 common to all four Geneva Conventions. Those provisions are
developed in and supplemented by Geneva Protocol II of 1977.
Both common Article 3 and Geneva Protocol II apply with equal force to all
parties to an armed conflict, government and rebels alike. Besides, government
troops and rebel forces must apply several other specific treaty rules relating
to internal conflicts, namely:
In simple words, the conclusion of the definitions can be drawn as:
- Article 19 of the 1954 Cultural Property Convention and its Second
Protocol of 1999 (the latter protocol has not yet entered into force at the
time of writing);
- Protocol II to the Conventional Weapons Convention, on Prohibitions or
Restrictions on the Use of Mines, Booby-Traps and Other Devices, as amended
on 3 May 1996;
- The Ottawa landmines treaty of 1997.
- The rules of customary international law certainly apply as well, in
particular the basic principles of the law of armed conflict we covered in
detail in earlier lessons, namely distinction, proportionality, military
necessity, limitation, good faith, and humane treatment.
- International armed conflicts exist whenever there is a resort to armed
force between two or more States.
- Non-international armed conflicts are protracted armed confrontations
occurring between governmental armed forces and the forces of one or more
armed groups, or between such groups arising on the territory of a State
[party to the Geneva Conventions]. The armed confrontation must reach a
minimum level of intensity and the parties involved in the conflict must
show a minimum of organization.
Apart from the definitions of both the conflicts, interpretation, and
understanding are also required to be kept in mind while dealing with the
- Statutes of the International Red Cross and Red Crescent Movement, art.
5, para. 2(g)
- J. Pictet, Commentary on the Geneva Convention for the Amelioration of
the Condition of the Wounded and Sick in Armed Forces in the Field, ICRC,
Geneva, 1952, p. 32
- ICTY, The Prosecutor v. Dusko Tadic, Decision on the Defence Motion for
Interlocutory Appeal on Jurisdiction, IT-94-1-A, 2 October 1995, para. 70
- D. Schindler, The different Types of Armed Conflicts According to the
Geneva Conventions and Protocols, RCADI, Vol. 163, 1979-II, p. 131.
- H.P. Gasser, International Humanitarian Law: an Introduction, in
Humanity for All: the International Red Cross and Red Crescent Movement, H.
Haug (ed.), Paul Haupt Publishers, Berne, 1993, p. 510- 511.
- ICTY, The Prosecutor v. Dusko Tadic, Judgment, IT-94-1-T, 7 May 1997,
para. 561-568; see also ICTY, The Prosecutor v. Fatmir Limaj, Judgment,
IT-03-66-T, 30 November 2005, para. 84
- For a detailed analysis of this criteria, see ICTY, The Prosecutor v.
Fatmir Limaj, Judgment, IT-03- 66-T, 30 November 2005, para. 135-170
- See D. Schindler, The Different Types of Armed Conflicts According to
the Geneva Conventions and Protocols, RCADI, Vol. 163, 1979-II, p. 147. For
a detailed analysis of this criteria, see ICTY, The Prosecutor v. Fatmir
Limaj, Judgment, IT-03-66-T, 30 November 2005, para. 94-134
- Additional Protocol II, art. 1, para. 1
- Statute of the ICC, art. 8 para. 2 (f): "It applies to armed conflicts
that take place in the territory of a State when there is a protracted armed
conflict between governmental authorities and organized armed groups or
between such groups"
- H.P. Gasser, International Humanitarian Law: an Introduction, in
Humanity for All: the International Red Cross and Red Crescent Movement, H.
Haug (ed.), Paul Haupt Publishers, Berne, 1993, p. 555.
- D. Schindler, The Different Types of Armed Conflicts According to the
Geneva Conventions and Protocols, RCADI, Vol. 163, 1979-II, p. 147
- Liesbeth Zegveld, Accountability of Armed Opposition Groups in
International Law, Cambridge: Cambridge University Press, 2002, p. 136