Case Summary: Military and Paramilitary Activities in and Against Nicaragua (Nicaragua v. United States) (1986)

1. Case Title & Citation

• Full Name: Case Concerning Military and Paramilitary Activities in and Against Nicaragua (Nicaragua v. United States)
• Citation: 1986 ICJ Rep. 14
• Decision Date: 27 June 1986

2. Court Name & Bench

• Court: International Court of Justice (ICJ)
• Bench Type: Full bench hearing on contentious cases
• Composition: Full bench of ICJ justices

3. Date of Judgment

Judgment delivered on 27 June 1986

4. Parties Involved

• Petitioner: Republic of Nicaragua (Plaintiff)
  • Accused the United States of unlawful military and paramilitary actions infringing its sovereignty
• Respondent: United States of America
  • Denied unlawful acts, invoked collective self-defense, and contested ICJ jurisdiction

5. Facts of the Case

Nicaragua alleged that the United States engaged in a range of unlawful military activities, including:

• Mining Nicaraguan harbors in 1984
• Attacks on Nicaraguan ports, oil installations, and naval bases
• Supporting Contra guerrillas attempting to overthrow the Nicaraguan government
• Imposing a general trade embargo and interrupting peaceful maritime commerce

The United States claimed these actions were justified as collective self-defense of El Salvador and other states allegedly threatened by Nicaragua.

Nicaragua brought the dispute to the ICJ for a judgment on violations of customary international law and treaties, particularly the 1956 Treaty of Friendship, Commerce and Navigation between the parties.

6. Issues Raised

• Whether the United States unlawfully used force against Nicaragua contrary to customary international law and the UN Charter
• Whether U.S. support to Contra rebels amounted to unlawful intervention in Nicaragua’s internal affairs
• Jurisdiction of the ICJ over this dispute despite U.S. objections
• Whether the U.S. could lawfully invoke collective self-defense to justify its actions
• Whether the U.S. breached obligations under the 1956 Treaty

7. Arguments of the Parties

Nicaragua’s Arguments:

• The U.S. violated Article 2(4) of the UN Charter prohibiting the use of force
• The U.S. breached customary international law by intervening and using force
• The trade embargo and mining violated the 1956 Treaty
• No armed attack by Nicaragua justified U.S. self-defense claims

United States’ Arguments:

• Claimed the ICJ lacked jurisdiction due to treaty reservations and political questions
• Argued self-defense rights under customary international law justified its actions
• Alleged Nicaragua supported armed opposition in El Salvador, necessitating collective self-defense

8. Judgment / Final Decision

The ICJ held that the United States violated international law by:

• Using force against Nicaragua through direct military actions and support to Contra forces
• Breaching sovereignty and the principle of non-intervention
• Violating the 1956 Treaty by mining harbors and imposing a trade embargo

Key Holdings:

• U.S. claims of collective self-defense were rejected as unjustified—no armed attack by Nicaragua occurred
• The ICJ affirmed its jurisdiction despite U.S. objections
• The Court ordered the U.S. to cease unlawful actions immediately and make reparations to Nicaragua
• The form and amount of reparations to be determined in subsequent procedures

9. Legal Reasoning / Ratio Decidendi

The Court’s legal reasoning was grounded in several fundamental principles of international law:

On Use of Force: The prohibition on the use of force under the UN Charter is absolute except for self-defense or Security Council authorization. Support of armed opposition forces in another state constitutes unlawful intervention.

On Collective Self-Defense: Collective self-defense requires an armed attack as per Article 51 of the UN Charter, which was absent in this case. The United States could not justify its actions under this doctrine without demonstrating that Nicaragua had committed an armed attack.

On Jurisdiction: The ICJ’s jurisdiction stemmed from the treaty clause providing for dispute resolution in relevant treaties. Political objections did not exclude judicial review of the matters presented.

On Treaty Obligations: The treaty obligations in the 1956 Treaty included non-interference and ensuring freedom of navigation, both of which were breached by U.S. actions.

Broader Principles: The case reaffirmed sovereignty, non-intervention, and peaceful dispute resolution principles as foundational pillars of international law.

10. Conclusion / Observations

This landmark judgment clarified the limits on use of force and external intervention in international relations. The decision rejected expansive claims of collective self-defense without a genuine armed attack and strengthened the role of the ICJ in adjudicating interstate disputes on sovereignty and treaty compliance.

The rulings have enduring significance for international law on state sovereignty, the prohibition of unlawful intervention, and the peaceful settlement of disputes. The case remains a critical precedent in debates over humanitarian intervention, regime change, and the lawful use of force in international relations.

Sources

This case summary is based on authoritative sources including ICJ official reports, legal databases, and academic analysis of the judgment. Key references include:

1. Nicaragua v. United States, Wikipedia
2. ICJ Official Case Summary (archived), 27 June 1986
3. Military and Paramilitary Activities Case Brief, Quimbee
4. Case documentation, Justia International Law
5. ICJ Reports and academic commentary from various legal institutions

This detailed case summary covers the essential legal and factual aspects of the Nicaragua v. United States case under international law.