Tutorial 4
When is the use of force approved?
The doctrine on the use of force = jus ad bellum. 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 will enter into force, namely: international humanitarian law = jus in
bello. International humanitarian law contains rules on warfare: it prescribes how to behave when
engaged in an armed confict. Jus in bello does not concern itself with the question whether a war
has been lawfully started (thus, whether the rules of jus ad bellum have been correctly applied).
The law on the use of force is one of the most controversial areas of international
law. The prohibition on the use of force by states is anchored in art. 2(4) UN Charter.
This contains not only the use, but also the threat of using force. The provision only
covers the prohibition of states relating to their international relations. (The ICJ had
problems about having jurisdiction in some cases, Rwanda-case)
MILITARY AND PARAMILITARY ACTIVITIES IN AND AGAINST NICARAGUA
(NICARAGUA V. UNITED STATES OF AMERICA)
The US had insisted on a ‘multilateral treaty reservation’ on the jurisdiction of the
Court. The Court could only apply and decide on customary law and said that: the
prohibition on the use of force is also part of customary international law.
Relevant paragraphs 176, 190, 193
176 [...] On one essential point, this treaty itself refers to pre-existing customary international law; this reference to customary
law is contained in the actual text of Article 51, which mentions the "inherent right” (in the French text the "droit naturel”) of
individual or collective self-defence, which "nothing in the present Charter shall impair” and which applies in the event of an
armed attack.
190. A further confrmation of the validity as customary international law of the principle of the prohibition of the use of force
expressed in Article 2, paragraph 4, of the Charter of the United Nations may be found in the fact that it is frequently referred to
in statements by State representatives as being not only a principle of customary international law but also a fundamental or
cardinal principle of such law...
193 [....] First, with regard to the existence of this right, it notes that in the language of Article 5 1 of the United Nations Charter,
the inherent right (or "droit naturel”) which any State possesses in the event of an armed attack, covers both collective and
individual self-defence. Thus, the Charter itself testifes to the existence of the right of collective self-defence in customary
international law. Moreover, just as the wording of certain General Assembly declarations adopted by States demonstrates their
recognition of the principle of the prohibition of force as defnitely a matter of customary international law, some of the wording
in those declarations operates similarly in respect of the right of self-defence (both collective and individual). Thus, in the
declaration quoted above on the Principles of International Law concerning Friendly Relations and Cooperation among States in
accordance with the Charter of the United Nations, the reference to the prohibition of force is followed by a paragraph stating
that: "nothing in the foregoing paragraphs shall be construed as enlarging or diminishing in any way the scope of the provisions
of the Charter concerning cases in which the use of force is lawful”.
This resolution demonstrates that the States represented in the General Assembly regard the exception to the prohibition of
force constituted by the right of individual or collective self-defence as already a matter of customary international law.
The controversy concerns two aspects:
A. The extent of the exceptions in the UN Charter, which are
a. Art. 51: self defence
b. Art. 42: use of force with the authorization of the UN Security Council
B. 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 international law more in general.
Art. 2 (4) UN Charter prohibition on the use of force follows from art. 2 (3) UN
Charter. It stipulates that states shall settle their international disputes by peaceful
means. Further rules are set out in articles 33-38 UN Charter. The Charter allows
for two exceptions to the prohibition on the use of force:
- Individual Self-defence article 51
The UN Security Council retains the competence to take decisions with respect to
the situation at hand.
LEGALITY OF THE USE OR THREAT OF NUCLEAR WEAPONS, ADVISORY
OPINION, INTERNATIONAL COURT OF JUSTICE
'This prohibition of the use of force is to be considered in the light of other relevant
provisions of the Charter. In Article 51, the Charter recognizes the inherent right of
individual or collective self-defence if an armed attack occurs. A further lawful use of
force is envisaged in Article 42, whereby the Security Council may take military
enforcement measures in conformity with Chapter VII of the Charter.'
Literature: Chapter 10 – International Law, Part 14 – E-learning, 1
Cases: 4: Nicaragua/ Legality of the use or Threat of Nuclear Weapons/ Oil Platforms/ Application on the
convention on the prevention and punishment of the crime of. Genocide
When is the use of force approved?
The doctrine on the use of force = jus ad bellum. 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 will enter into force, namely: international humanitarian law = jus in
bello. International humanitarian law contains rules on warfare: it prescribes how to behave when
engaged in an armed confict. Jus in bello does not concern itself with the question whether a war
has been lawfully started (thus, whether the rules of jus ad bellum have been correctly applied).
The law on the use of force is one of the most controversial areas of international
law. The prohibition on the use of force by states is anchored in art. 2(4) UN Charter.
This contains not only the use, but also the threat of using force. The provision only
covers the prohibition of states relating to their international relations. (The ICJ had
problems about having jurisdiction in some cases, Rwanda-case)
MILITARY AND PARAMILITARY ACTIVITIES IN AND AGAINST NICARAGUA
(NICARAGUA V. UNITED STATES OF AMERICA)
The US had insisted on a ‘multilateral treaty reservation’ on the jurisdiction of the
Court. The Court could only apply and decide on customary law and said that: the
prohibition on the use of force is also part of customary international law.
Relevant paragraphs 176, 190, 193
176 [...] On one essential point, this treaty itself refers to pre-existing customary international law; this reference to customary
law is contained in the actual text of Article 51, which mentions the "inherent right” (in the French text the "droit naturel”) of
individual or collective self-defence, which "nothing in the present Charter shall impair” and which applies in the event of an
armed attack.
190. A further confrmation of the validity as customary international law of the principle of the prohibition of the use of force
expressed in Article 2, paragraph 4, of the Charter of the United Nations may be found in the fact that it is frequently referred to
in statements by State representatives as being not only a principle of customary international law but also a fundamental or
cardinal principle of such law...
193 [....] First, with regard to the existence of this right, it notes that in the language of Article 5 1 of the United Nations Charter,
the inherent right (or "droit naturel”) which any State possesses in the event of an armed attack, covers both collective and
individual self-defence. Thus, the Charter itself testifes to the existence of the right of collective self-defence in customary
international law. Moreover, just as the wording of certain General Assembly declarations adopted by States demonstrates their
recognition of the principle of the prohibition of force as defnitely a matter of customary international law, some of the wording
in those declarations operates similarly in respect of the right of self-defence (both collective and individual). Thus, in the
declaration quoted above on the Principles of International Law concerning Friendly Relations and Cooperation among States in
accordance with the Charter of the United Nations, the reference to the prohibition of force is followed by a paragraph stating
that: "nothing in the foregoing paragraphs shall be construed as enlarging or diminishing in any way the scope of the provisions
of the Charter concerning cases in which the use of force is lawful”.
This resolution demonstrates that the States represented in the General Assembly regard the exception to the prohibition of
force constituted by the right of individual or collective self-defence as already a matter of customary international law.
The controversy concerns two aspects:
A. The extent of the exceptions in the UN Charter, which are
a. Art. 51: self defence
b. Art. 42: use of force with the authorization of the UN Security Council
B. 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 international law more in general.
Art. 2 (4) UN Charter prohibition on the use of force follows from art. 2 (3) UN
Charter. It stipulates that states shall settle their international disputes by peaceful
means. Further rules are set out in articles 33-38 UN Charter. The Charter allows
for two exceptions to the prohibition on the use of force:
- Individual Self-defence article 51
The UN Security Council retains the competence to take decisions with respect to
the situation at hand.
LEGALITY OF THE USE OR THREAT OF NUCLEAR WEAPONS, ADVISORY
OPINION, INTERNATIONAL COURT OF JUSTICE
'This prohibition of the use of force is to be considered in the light of other relevant
provisions of the Charter. In Article 51, the Charter recognizes the inherent right of
individual or collective self-defence if an armed attack occurs. A further lawful use of
force is envisaged in Article 42, whereby the Security Council may take military
enforcement measures in conformity with Chapter VII of the Charter.'
Literature: Chapter 10 – International Law, Part 14 – E-learning, 1
Cases: 4: Nicaragua/ Legality of the use or Threat of Nuclear Weapons/ Oil Platforms/ Application on the
convention on the prevention and punishment of the crime of. Genocide
