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Nicaragua v. The United States of America

The facts

July 1979 Sandinista government in Nicaragua 1981 Nicaragua supported armed groups in El Salvador 1983 USA fund for the Contras 1984 USA laid mines in Nicaraguan ports; infringement of

Nicaraguan air space; economic measures against Nicaragua

9 April 1984Nicaraguas claim at the ICJArguments

Nicaragua: Violations of treaty obligations (supplying military paramilitary

actions)

Violations of international law (sovereignty, use of force,intervention)

ReparationsArgumentsUSA:

Nicaragua supported armed groups Cross border military attacks Collective self defence Why Customary Law was Important in this Case Before evaluating the case on the merits, the Court had to

decide whether the U.S. reservation stripped the Court of its

jurisdiction.

The reservation excluded from Article 36 of the Statute of ICJdisputes arising under a multilateral treaty, unless (1) allparties to the treaty affected by the decision are also parties to

the case before the Court, or (2) the United States of America

specially agrees to jurisdiction.

The Court concluded that the reservation is applicable in thiscase because

U.S. did not specially agree to the jurisdiction in thiscase, and

Parties to the treaty affected by the decision werenot all parties before the court. Parties to the

dispute included United States and Nicaragua.

However, U.S. claimed it was acting in collective self-

defense on behalf of El Salvador. El Salvador was not

a party before the Court. The Court determined El

Salvador would be affected by its judgment.

As a result, the Court determined that the reservation barred itfrom applying the multilateral treaties to this case.

But the Court did not stop there, however. The Court viewed the reservation as a limitation on the type of

law that the court could apply (multilateral treaties), not as a

limitation on its overall jurisdiction to hear the case.

Thus other sources of law under Art. 38 of the Statute of the ICJwere still applicable, including customary international law.

U.S. argued that customary rules whose content is identical tothat of the treaties cannot be applied due to the U.S.

reservation.

The Court rejected this and held that just because a treatyincorporates customary international law, it does not deprive

the customary law of its applicability distinctly from the treaty.

Thus according to the Court, treaties and customary law haveindependent existence and apply separately, even when both

deal with the same subject matter.

Court states . . . Even if the customary norm and the treatynorm were to have exactly the same content, this would not be

a reason for the Court to hold that the incorporation of the

customary norm into treaty-law must deprive the customary

norm of its applicability as distinct from that of the treaty

norm . . . . More generally, there are no grounds for holding

that when customary international law is comprised of rules

identical to those of treaty law the latter supervenes the

former, so that the customary law has no further existence of

its own. I.C.J. Reports 1986, p. 94-95, para. 177 (emphasis

added).

Example:

If two States (A and B) are subject to a bilateral treaty and State A

breaches, State B would no longer be obligated to comply with

that treaty. However if there was also customary law applicable to

the situation, the two States would still have to abide by it,

independently of the treaty.

Which rules of customary international law were addressed in

the case?

1. Not to intervene in the affairs of another State.2. Not to use force against another State. Art. 2(4) UN Charter3. Right to self-defence. Art. 51 UN Charter4. Not to violate its sovereignty.5. Collective counter-measures in response to conduct not

amounting to armed attack

Opinio Juris and State Practice

Once the Court had decided to apply customary law, it had toascertain which rules of customary law were relevant to this

case.

Therefore, the Court considered whether a customary ruleexists in the opinio juris of States, and satisfy itself that it is

confirmed by practice.

It is important to really check the material of customaryinternational law in the actual practice and opinio juris of

States. It doesnt matter if these rules have already been

collected by several treaties or any other intruments.

The Court also noted that both Nicaragua and US had aconsiderable degree of agreement as to the content of the

customary international law related to the non-use of force and

non-intervention.

But, the fact that States declare their recognition of certainrules is not sufficient for the Court to consider these as being

part of customary internt. law and as applicable as such to

those States. The Court must not disregard the rol played by

general practice. The Court must satisfy itself that the

existences of the rule in the opinio juris of States is confirm by

practice.

Opinio Juris and State Practice Thus, the Court held that the attitude of the parties and States

towards certains General Assembly Resolutions could be

indicative of opinio juris. (189. As regards the United States in

particular, the weight of an expression of opinio juris can

similarly be attached to its support of the resolution of the SixthInternational Conference of American States condemning

aggression (18.02.28) and ratification of the Montevideo

Convention on Rights and Duties of States (26.12.33).

Controversy:Some scholars say that the Court should first look to state practice

and not to opinio juris. And since the Court in this case looked to

opinio juris without emphasizing state practice, it got it

backwards.

Opinio Juris and State Practice Some others say that it is not normally even necessary to prove

the existence of opinio juris when you have firm evidence of

state practice. In the Nicaraguan case the ICJ demanded very

little evidence of actual state practice, where it saw clear

evidence of opinio juris. It found evidence of opinio juris by

looking to the General Assembly resolutions. (Int. LawAssociationLondon Conference 2000)

If there is enough evidence of state practice, opinio juris is notalways necessary, and usually if it does exist, courts use it only

to confirm the existence of state practice as indicative of

customary law.

But, where there is little evidence of state practice, court willmake up for that with greater evidence of opinio juris and vice

versa.

1. Use of Force

Party Agreement General Assembly Resolution 2625 (XXV)

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Resolution of The Sixth International Conference of AmericanStates Concerning Aggression 18 Feb 1928

Montevideo Convention on the Rights and Duties of States 26December 1933

2. Self Defence

Party Agreement UN Charter Article 51 General Assembly Resolution 2625 (XXV) General Assembly Resolution 3314 (XXIX) Charter of Organisations of American States International Treaty of Reciprocal Assistance 1947

3. Non-intervention

Numerous declarations and resolutions Corfu Channel (Merits) United Kingdom v Albania 1949 ICJ

Reports 4

4. Collective counter-measures in response to conduct notamounting to armed attack

Counter-measures is an exemption of non-interventionprinciple;

Counter-measures is analogous to the right of self-defence inthe case of armed attack;

ICJ: armed attack must be understood as including not merelyaction by regular armed forces across an international border,

but also sending by or on behalf of a State of armed bands,

groups, irregulars or mercenaries, which carry out attacks of

armed force against another State of such gravity as to amount

to an actual armed attack conducted by regular forces, or its

substantial involvement therein.

5. State sovereigntyThe concept of sovereignty extends to the internal waters and territorial

sea of every State and to the airspace above its territory:

Art. 2(1) of the UN Charter; Art. 1 of the Chicago Convention on International

Civil Aviation (1944);

Geneva Convention on the Territorial Sea (1958); UN Convention on the Law of the Sea (1982). Laying of mines by another State is infringement of

the freedom of communications and of maritime

commerce.

6. Humanitarian law A breach of the principles of humanitarian law underlying the

specific provisions of Hague Convention (Art. 3 and 4);

United States commited violation of Art. 3 of the fourth GenevaConvention;

The conflict between Contras forces and those of theGovernment of Nicaragua is an armed conflict which is "not of

an international character";

Obligation on the United States Government, in the terms ofArt. 1 of the Geneva Convention is to "respect" the Conventions

and even "to ensure respect" for them "in all circumstances"

(general principle of humanitarian law)

How did the ICJ address differences in opinion regarding thecontent of the substantive rule(s)?

The court found in its legal verdict that the US was in breach ofits legal obligations under customary international law not to

use force against another state, not to intervene in its

affairs, not to violate its sovereignty, not to interrupt

peaceful maritime commerce, and in breach of its obligations

under Article XIX of the Treaty of Friendship, Commerce and

Navigation between the Parties signed at Managua on 21

January 1956.

It said that it was not necessary that the practice in questionhad to be in absolutely rigorous conformity with the

purported customary rule.

How did the ICJ address differences in opinion regarding thecontent of the substantive rule(s)?

The court continued: In order to deduce the existence ofcustomary rules, the court deems it sufficient that the conduct

of states should, in general, be consistent with such rules, and

that instances of state conduct inconsistent with a given rule

should generally have been treated as breaches of that rule, not

as indications of the recognition of a new rule.

If a State acts in a way that is incompatible with a recognizedrule, but then defends its action by trying to appeal to an

exception to that rule, then whether or not the State's conduct

is in fact justifiable on that basis, the significance of that

attitude is to confirm rather than to weaken the rule.