The expression “internationalized armed conflicts” is not a legal expression as such and does not imply a third category of armed conflicts.  The expression rather describes situations of non-international armed conflicts with a dimension that is said to be “international”. This dimension can take several forms:

1) One or more third States or an international/regional organization (the States or the organization acting through a multinational force) intervene in support of a state involved in an armed conflict against an organized armed group 2) One or more third States or an international/regional organization (the States or the organization acting through a multinational force) intervene in support of an organized armed group involved in an armed conflict against a State 3) Other possible combinations between situations 1), 2) and 3).

From a legal point of view, these situations can be translated into three specific cases:

-        Some remain a non-international armed conflict -        Others become an international armed conflict -        Others become “mixed” conflicts. In such conflicts, depending on the nature of parties to the conflict, IHL of non-international armed conflicts applies to the relations between some parties (e.g. between an armed group and an intervening outside State), while IHL of international armed conflicts applies to other relations, e.g. between to States intervening militarily in support of two adverse parties of a NIAC)



Yemen, UN Report on the Armed Conflict since 2014

ILC, Draft Articles on State Responsibility (Part A., Art. 8)

ICJ, Nicaragua v. US (paras 219 and 254)

Case Study, Armed Conflicts in the former Yugoslavia (9 and 26)

ICTY, The Prosecutor v. Tadic (A. Para. 72, C. Paras. 87-162)

ICTY, The Prosecutor v. Rajic (Paras. 11 and 13-31)

US, Kadic et al v. Karadzic

Switzerland, Military Tribunal of Division 1, Acquittal of G.

Case Study, Armed Conflicts in the Great Lakes Region (3. A)

India, Press Release, Violence in Kashmir

Philippines, Application of IHL by the National Democratic Front of the Philippines

Georgia/Russia, Human Rights Watch’s Report on the Conflict in South Ossetia [Paras 7-15]

Georgia/Russia, Independent International Fact-Finding Mission on the Conflict in South Ossetia [Paras 2-27]

Syria, Press conference with French President Francois Hollande and Russian President Vladimir Putin

Libya, NATO Intervention 2011

ICRC, International Humanitarian Law and the challenges of contemporary armed conflicts in 2015 (Paras 27, 57-59)

ICTY, The Prosecutor v. Radovan Karadzic

Libya, Report of the Office of the UN High Commissioner for Human Rights (2014/15)

Central African Republic: Sexual Violence by Peacekeeping Forces

Central African Republic, Report of the UN Independent Expert, July 2016

Syria, Report by UN Commission of Inquiry (March 2017)

Italy, Use of force against ambulances in Iraq

Syria, the Battle for Aleppo

Iraq/Syria/UK, Drone Operations against ISIS

United Kingodm, Arms Trade With Saudi Arabia

International Criminal Court, Trial Judgment in the Case of the Prosecutor V. Jean-Pierre Bemba Gombo

Iraq, The Battle for Mosul

Eastern Ukraine, Attacks Against and Military Use of Schools

Eastern Ukraine, OHCHR Report on the Situation: November 2016 - February 2017

UN, Working Group on the use of Mercenaries: Preliminary Findings of Mission to Ukraine

Central African Republic, No Class: When Armed Groups Use Schools

Syria: Attacks on Oil Infrastructure

Eastern Ukraine: Detention And Death Sentences By Armed Groups

The Netherlands/Ukraine, Classification of the Situation and Combatant Status (2014)


GASSER Hans-Peter, “Internationalized Non-International Armed Conflicts: Case Studies of Afghanistan, Kampuchea and Lebanon”, in American University Review,Vol. 33/1, 1983, pp. 145-161.   SCHINDLER Dietrich, “The Different Types of Armed Conflicts According to the Geneva Conventions and Protocols”, in Collected Courses, Vol. 163, 1979, pp. 119-163.   SCHINDLER Dietrich, International Humanitarian Law and the Internationalization of Internal Armed Conflict, San Remo, International Institute of Humanitarian Law, 1981, 15 pp.   STEWART James G., “Towards a Single Definition of Armed Conflict in International Humanitarian Law: a Critique of Internationalized Armed Conflict”, in IRRC, No. 850, June 2003, pp. 313-349