Week 1 – Sources of IHL, NIAC and IAC
History of IHL: origins
After the battle memory of Solferino, call upon the civilized nations to look after the
victims of an armed conflict (Henry witnessed the aftermath)
1862: Henry Dunant, A Memory of Solferino
o Called for establishment of societies for the relief of the wounded – organizations of
experienced volunteers, commanders in the field who would provide immediate
treatment and for states to agree by treaty
1863 Lieber Code
1863 ICRC is founded
1864 Geneva Convention for wounded and sick armed forces in the field
1868 St. Pietersburg Declaration (exploding bullets, disproportionate use of force, prevent
unnecessary suffering)
1899 and 1907 Hague Conferences
History of IHL: developments
Convergence Hague Law and Geneva Law
o Means and methods
o Protection of vulnerable
More categories of protected persons and better protection (e.g. civilians)
Shift from “war” to armed conflict (de jure) (no declaration of war required anymore)
Increased importance of civil wars
IHL within PIL
IHL is a field within PIL
o Based on model of sovereign equal states
o Same formal sources
o Same rules of interpretation
IHL is different from (although overlaps with)
o Jus ad bellum (law governing use of force)
o Human rights
o International criminal law
Sources of IHL
Wounded and sick armed forces in the field
o GC (I) 1949
Wounded, sick, shipwrecked and armed forces at sea
o GC (II) 1949
Prisoners of war
o GC (III) 1949
Civilians
o HC (IV) 1907 (regulates conduct of hostilities)
o GC (IV) 1949
GC’s are pretty much universally ratified customary international law
Sources of IHL: core treaties
Hague Regulations annexed to Hague Convention IV (1907) [38 state parties]
Geneva Convention I-IV (1949) [196 states]
o Wounded and sick armed forces in the field
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, o Wounded, sick and shipwrecked at sea
o POWs
o Civilians
Additional Protocols I-II (1977)
o IACs [174 parties]
o NIACs [168 parties]
Sources of IHL: customary IHL
Important sources because not all treaties universally ratified
o Major military powers not party to AP I
Treaty regulation of NIACs is limited
o Common Articles 3 and AP II
2005 ICRC Study
o See List of Rules
Convergence between law applicable to IAC and NIAC
And soft law (useful instructions and guidance for states and non-state actors, often
reiterate/elucidate existing international law norms)
o Case law, manuals, guidelines, codes
Scope of application: IAC
State v state (ratione personae)
Situations (ratione materiae) [CA 2 GC]
o Declared war
o “any other armed conflict” (certain threshold of violence usually needed, some
argue)
- (also first shot theory, you want them to apply as early as possible
protection of LOAC). Threshold for IAC is first shot theory: any use of force by
one state against another state’s armed force, or any total or partial
occupation of another state’s territory irrespective of whether it is opposed,
will trigger the existence of an armed conflict between those states
o (belligerent) occupation
o Wars of national liberation (suffer from foreign invasion) [1(4) AP I]
Applicable law: GC I-IV + AP I + HR 1907 + CIHL
Recent examples
o Iran – Iraq (1980 – 88), Russia – Ukraine (2014/2022 – present)
LOAC binds states, nonstate actors and individuals all persons who may be affected by
conflict, on any side, in any way, are covered by the ambit of the law
Law in NIAC =/= law in IAC (fewer rules in NIAC)
Temporal scope: when there is ‘an armed conflict’. Generally deemed to no longer be
applicable when there is a general close of military operations [GC IV 6(2) + AP I 3(b)(1)]; an
end of captivity/detention under GC III relating to POW [GC III 5(1)]; end of military
occupation – may be one year after general close of military operations [GC IV 6(3)], except
in cases where OP continues to exercise functions of government
Spatial application IHL
Applies in all areas covered by actual armed conflict or belligerent occupation applies to
territory of belligerent states [GC IV art 2]
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,Principle of unity of territory
Even if the fighting is localized in one area, LOAC applies in entirety of territory, even in areas where
no active hostilities take place (NIAC Akayesu, IAC Tadic)
Scope of application: NIAC (state not party to AP)
State v organized armed group; OAG v OAG (ratione personae)
Situations (ratione materiae)
“protracted (intense) armed violence between governmental authorities and OAGs or
between such groups
- ICTY, Prosecutor v Tadic
Criteria
o Level of organization
o Intensity of conflict
Applicable law: CA 3 + CIHL
o State party to AP II?
o Or only Tadic?
State v OAG (ratione personae)
Situations (ratione materiae) [1(1) AP II]
o NIAC within one state, in which OAG has
Control over part of state’s territory
Ability to carry out sustained and concerted military operations and to
implement AP II
Applicable law: CA III + AP II + CIL
Recent examples of NIACs: Libya, Yemen
Temporal scope: LOAC applies until a peaceful settlement is achieved (Tadic)
IACs and NIACs: ratio and difficulties
Difference is rooted in nature of PIL
State are reluctant to acknowledge NIACs, OAGs might be eager (receive recognition of an
armed conflict, that they are legit)
Denialism and secrecy make determination of applicable law difficult
Concept from 1949 difficult to apply in 2022
Conflicts, borders and governments are fluid
o IACs can turn into NIACs and vice versa
Difficulties in conflicts involving multiple parties
o And/or international organizations
An AP II conflict is one that takes place between the armed forces of a state and dissident armed
forces or other OAGs that control sufficient territory so ‘as to enable them to carry out sustained and
concerted military operations’. Unlike CA 3, the protocol does NOT apply to armed conflicts between
OAGs. AP II applies only to states that are party to the protocol and therefore does not apply to
armed forces of a non-signatory state that is engaged in a conflict on the territory of a state party.
Principle of distinction
Art 48 AP I
Considered customary
Two-fold obligation: 1. Parties to armed conflict must at all times distinguish between
civilians and combatants 2. Attacks only directed against military objects and objectives
Art 58(b) and 51(7) AP I military installations in civilian-dense areas
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, Principle of discrimination (prohibition on indiscriminate attacks)
Art 51(4) AP I
Principle of military necessity
Parties to conflict only adopt measures necessary to weaken enemy and achieve their
surrender; not necessary to bring about total destruction of enemy, its armed forces or
property
Principle of proportionality
Art 51(5)(b) AP I
Any military measures taken by parties to conflict must be proportionate – military
advantage gained by particular operation must outweigh damage caused to civilians and
civilian objects
Collateral damage allowed, as long as it’s proportionate
Prohibition on causing unnecessary suffering and superfluous injury
Principle prohibits any injury against combatants greater than strictly necessary to achieve
military objectives, which uselessly aggravates suffering of wounded personnel, or otherwise
renders their death inevitable
Designed to apply to combatants, rather than civilians
Principle of neutrality
Upon commencement of armed conflict, all states not already party to conflict must decide
whether to join hostilities, or not become involved (neutral). Neutral states enjoy
fundamental rights (e.g. may not be attacked). Belligerent parties must respect neutrality
To enjoy rights of neutrality, neutral state has duties: duty of abstention (may not engage in
conflict); duty of impartiality; duty of prevention (must defend its neutral status)
Principle of humanity
No unnecessary suffering
The principle of humanity forbids the infliction of all suffering, injury or destruction not
necessary for achieving the legitimate purpose of a conflict
IAC
CA 2 (scope of application)
o Wars of national liberation [AP I art 1(4)]
Armed conflict: recourse to armed force (by one state) against another state, regardless of
the reasons or intensity of confrontation (Tadic)
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