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Week 3: Human Rights
Module 14: The Prohibition of the Use of Force under IL
There are specific rules on how to behave during war (like the 1949 Geneva Conventions). War and
peace have come to be seen as more fluid conditions, sometimes governed by specific rules, but
sometimes by general rules. There is little doubt, for instance, that human rights law continues to
apply even in wartime.
• Jus ad bellum: the doctrine on the use of force (Article 2(4) UN Charter: prohibition on the use of
force). These rules regulate when force may be used legitimately. In a case where force is used
(irrespective of whether it is done legitimately), a succeeding regime of law enters into force, namely
international humanitarian law (jus in bello). Note: the use of force is part customary IL as confirmed
by the ICJ in Nicaragua, [para 176/190/193].
• Jus in bello: international humanitarian law contains rules on warfare: it prescribes how to behave
when engaged in an armed conflict. Jus in bello does not concern itself with the question whether a
war has been lawfully started (whether the rules of jus ad bellum have been correctly applied). These
are the rights that count during war.
As a general rule, warfare is nowadays prohibited. Under the UN Charter, there is a well-nigh total ban
on the use of force. The use of force is made up of two different regimes:
I. The Charter regime.
II. The customary regime: which according to observers, may be more flexible than the Charter
regime.
The UN Charter and the Use of Force
Article 2(4) UN Charter follows from Article 2(3) UN Charter. which stipulates that states shall settle
their international disputes by peaceful means. (3) is further developed in Chapter VI (Articles 33-38).
(4) not only prohibits the actual use of force, but also the threat of force – still it is not entirely
waterproof. One thing to note is that the prohibition only affects the activities of states in their
international relations.
This prohibition has a broad scope. Meaning that there are not a lot of manifestations of the use of
force that would be consistent with the purposes of the UN, and that would not go against the
‘territorial integrity or political independence’ of states. This broad prohibition found almost immediate
support from the ICJ, deciding the Corfu Channel case in 1949. [para. 4] Mines in the Corfu Channel,
under Albanian jurisdiction, had cost the lives of several British Sailors, and the Court would hold
Albania responsible even though Albania claimed it had not itself laid those mines. More to the point,
however, a British response action in order to sweep for mines in the Corfu Channel several weeks
later was also roundly condemned by the Court. The UK offered two justifications, and both were
rejected by a unanimous (on this point) ICJ:
I. The UK suggested that its minesweeping operation (Operation Retail) had as its main
function the gathering of evidence. The Court dismissed this as a new theory of intervention
which manifested a ‘policy of force’ that could easily be abused, and which would seem to be
reserved for powerful states only.
II. The UK classified the operation as one of ‘self-help’ or ‘self-protection’, but this too was
rejected, as the minesweeping operation violated Albania’s territorial integrity regardless of
the intentions behind it. Without overtly relying on the new Charter (possibly for the good
reason that Albania had not yet been admitted into UN membership), the Court nonetheless
confirmed that the prohibition of the use of force was to be taken seriously.
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Controversy remains as to the lawful exceptions to Article 2(4) UN Charter. This controversy concerns
two aspects in particular:
I. The extent of the exceptions in the UN Charter, which are:
a. Self defence (Article 51 UN Charter).
b. Use of force with the authorisation of the UN Security Council (Article 42 UN Charter).
As the ICJ confirmed in its AO on the Legality of the Threat or Use of Nuclear Weapons, para. 38.
II. Possible exceptions outside the UN Charter; in particular humanitarian intervention. Both
humanitarian intervention and terrorist acts pose challenges to the UN Charter system on the
use of force and to IL more in general. THIS IS A JUSTIFICATION GROUND.
ICJ’s jurisdiction about the use of force and self-defence
The ICJ has rarely had the opportunity in contentious proceedings to say much about the use of force
and self-defence as regulated in the Charter. Often the Court had to conclude that it lacked the
jurisdiction to proceed. In yet other case, the Court, while having jurisdiction, was not in a position to
apply the UN Charter due to restrictions on its jurisdiction:
● Nicaragua: the US had famously insisted on a so-called multilateral treaty reservation in its
acceptance of the Court’s jurisdiction; the Court could, in disputes involving multilateral
treaties, only apply these multilateral treaties if all parties possibly affected by the judgement
were also parties to the proceedings. As a result, the Court was forced to decide on the basis
of customary international law, and found that the customary prohibition on the use of force
continued to exist alongside the Charter prohibition [para. 176].
● Oil Platforms: by this time the US had terminated its acceptance of the Court’s compulsory
jurisdiction (it did so in the aftermath of Nicaragua). Consequently, the Court, in Oil Platforms,
saw its jurisdiction limited to application of the 1955 Treaty of Amity concluded between Iran
and the US – again, then, the UN Charter escaped scrutiny. And the first decision of the Court
involving the use of force involved Albania, at the time not yet a member of the UN and thus
not bound by the Charter’s provisions. As a result, there is only one contentious case, where
the Court had the opportunity to pay some attention to the Charter provisions involving the
use of force [para. 161]:
● Armed Activities: the Court held that Article 2(4) was a cornerstone of the Charter, and that
the provision on self-defence had to be read narrowly. This provision did not ‘allow the use of
force by a State to protect perceived security interests’ beyond the wording of Article 51,
although the Court stopped short saying that an armed attack must indeed already have
occured. While Uganda argued that it had occupied towns and airports in the DRC not for the
purpose of overthrowing the DRC government but for its own perceived security needs, the
Court did not accept the argument. Uganda, in doing so, had violated the principles of
non-intervention and the non-use of force: Uganda’s unlawful military intervention amounted
to a ‘grave violation of the prohibition of the use of force expressed in Article 2(4) [para. 148,
165].
Challenges: Humanitarian Intervention and Terrorist Acts
The primary international legal framework on the use of force, the UN Charter, provides for two main
avenues to a lawful use of force:
I. Self defence (Article 51 UN Charter): allows states their ‘inherent’ right of self-defence, but
only, it seems, until the Security Council steps in. The right of self-defence also forms part of
customary international law, as confirmed by the ICJ in the Nicaragua case. That being said,
the right to self-defence is not boundless or open-ended. Certain criteria have to be met for a
state to lawfully exercise the right to self-defence. These criteria, which are derived both from
Article 51 and customary international law, concern the:
a. Occurrence of an armed attack: it is generally understood that a state needs to be
subjected to a significant armed attack (e.g. not minor border skirmishes) in order to
invoke its right to self-defence. The threat must be imminent.
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b. Necessity: the resort to the use of force in self-defence has to be a measure of the
last resort to thwart an attack. Means that there are no alternative means to an armed
attack [if there are means that do not constitute the use of force and are equally
effective then Article 51 does not apply!].
c. Proportionality: the proportion of such use of force in self-defence has to be limited to
a level that is minimally sufficient to repel an armed attack. The reaction has to be
functional to repeal the armed attack.
● Three forms: I) when the harm that you are conflicting is much greater than
the benefit that you get II) tict for tact and III) ends means.
Together, b and c, imply that self-defence may not be punitive; the point of
self-defence is to repel an attack, not to pursue the attacker.
Immediate: response to an immediate attack.
ICJ confirmed these requirements in Nicaragua.
The ICJ dealt with the meaning and scope of these requirements in several of its cases,
notably: Nicaragua [para. 229-237], Oil Platforms [para. 73, 76, 77], AO on the Legality of
the Threat or Use of Nuclear Weapons [para. 41]:
● Oil Platforms: the World Court held that the requirement of necessity was more than
just a phrase. Confronted with possible minelaying by Iran, the US responded by
attacking Iranian oil platforms on two separate occasions. This, the Court felt, was
inappropriate, as there had been little evidence to suggest that those platforms had
been used for military activities or had served as the basis for Iran’s alleged
minelaying. Instead, as the US in part conceded, the platforms had been ‘targets of
opportunity’: this rendered the attack on them unnecessary for purposes of invoking
the customary law on self-defence. The Court’s analysis also suggests, quite
naturally, that necessity and proportionality are cumulative criteria; since the US had
been unable to show necessity, its self-defence argument had already failed, para 76.
Collective self defence (Article 51 UN Charter): this means that a state may resort to force in
the defence of another state. The ICJ dealt with the right of collective self-defence in detail in
the Nicaragua case. The Court held that the state desiring other states to engage in
collective self-defence on its behalf would 'normally make an express request to that effect'
[para. 232]. An example is NATO.
II. Use of force with the authorisation of the UN Security Council (Article 42 UN Charter): the UN
Security Council may also act under Article 42 after a state or several states have acted
under Article 51, on the basis of the right to self-defence or the right to collective self defence,
respectively.
Humanitarian intervention poses a challenge to the UN Charter system on the use of force because, although it is
not envisaged in the UN Charter, states have used humanitarian intervention to legitimise the use of force outside
the Charter system.
Another problematic aspect concerns the question of how to deal with the use of force by non-state
actors, e.g. terrorist groups. Traditionally, international law focuses on regulating force used by and
among states. The UN Charter system on the use of force primarily envisages scenarios of
large-scale, cross-border military conflict between states. International terrorist attacks bring
asymmetry to this scenario as they involve non-state actors and small-scale, non-systematic attacks
that do not necessarily satisfy the requirement of armed attack under Article 51 of the UN Charter.
Concerning the use of force by non-state actors, the further question that arises is whether such
behaviour could be attributed to the relevant state or states. International judicial bodies have applied
two different doctrines to determine the level of control required in order to attribute the acts of
