Authored By: Nowrin Jahan Borna
Gopalganj Science and Technology University
Case Name: Concerning Military and Paramilitary Activities in and against Nicaragua (Nicaragua v. United States of America)(1986)
[1986] I.C.J. 14
Court Name: ICJ (International Court of Justice).
Date of Introduction: 9 April,1984.
Date of Judgement: June 27, 1986.
Parties Involved:
Petitioner (Applicant) : Republic of Nicaragua.
Respondent (Defendant) : United States of America.
Judges sitting : Nagendra Singh, Guy Ladreit de Lacharrière, Roberto Ago, Mohammed Bedjaoui, Taslim Olawale Elias, Manfred Lachs, Kéba Mbaye, Ni Zhengyu, Shigeru Oda, José María Ruda, Stephen Schwebel, José Sette-Camara, Robert Jennings, Claude-Albert Colliard (ad hoc)
Background of the Dispute :
At the start of the 1980s, Nicaragua was ruled by a Sandinista government that replaced the Somoza dictatorship through a revolution.1 The government of the United States did not support the Sandinistas because of their alignment with Cuba and the Soviet Union during the Cold War era.2The U.S. began funding the Contras, anti-governmental militant groups seeking the overthrow of the Sandinista government.3
Claims Made By Nicaragua:
In its application lodged on April 9, 1984, Nicaragua made the following allegations before the ICJ:
● Supported, trained, armed, financed the Contras.4
● Conducted direct military operations, such as mining Nicaraguan harbors.5
● Affected the sovereignty and integrity of Nicaragua.6
Arguments of the Parties:
Nicaragua’s Arguments
Denial of Sovereignty: Nicaragua charged that the United States interfered with the internal affairs of the former by training, arming, and funding the Contras.7
Use of Unlawful Force: The harbor mining and military intervention in Nicaragua was cited in breach of Article 2 (4) of the Charter of the United Nations and customary international law in nature.8
Non-Intervention Principle: Nicaragua specifically pointed out that “the United States’ actions violated the principle of non-intervention, a principle that constitutes the cornerstone of international law.”9
Breaches of Treaties: Nicaragua charged that “the U.S. breached the Friendship, Commerce, and Navigation Treaty of 1956 through activities that disrupted the peaceful commerce” between the countries10
Reparations: Nicaragua demanded that reparation be made for the damages resulting from U.S.11
United States’ Arguments:
Jurisdiction Challenge: The U.S. contended that the ICJ had no jurisdiction with regards to the matters Nicaraguan claimed, as they were based on “multilateral treaties, such as the UN Charter, to which the U.S. had made reservations to exclude ICJ jurisdiction.”12
Self-Defense Claim: The U.S. claimed it acted legally as collective self-defense against suspected activities by Nicaragua in cooperating with rebels inside El Salvador.13
Denial of Armed Attack: The U.S. based its action on the belief that an attack existed through Nicaragua’s backing of insurgents in neighboring countries. Non-appearance: The U.S. refused to participate in the merits phase after the jurisdiction was confirmed, thus not participating in merits.14
Judgement
Status of Appeal: This was not an appeal but a contentious case brought directly by Nicaragua against the United States. The ICJ accepted jurisdiction despite U.S. objections and proceeded to the merits. Later, the U.S. withdrew from participation, but the Court continued. So there was no “appeal allowed/dismissed/modified” because, instead, the ICJ upheld Nicaragua’s claims.15
Findings: The United States had committed the following violations in terms of international law:
● It supported, trained, armed, and financed the Contras.16
● Mining Nicaraguan harbors and conducting military operations against it.17
● Breach of the principle of non‑intervention and prohibition of the use of force.18
● Violating the 1956 Friendship, Commerce, and Navigation Treaty.19
There were grounds to reject the U.S. claim of collective self‑defense because:
● As a result, no armed attack attributable to Nicaragua had been proven.
● El Salvador had not presented a proper request for help.
● The U.S. failed to notify the UN Security Council as required under Article 51 of the UN Charter.20
Directions:
➢ The Court ruled that the USA must halt its illegal actions against Nicaragua.
➢ The Court ordered the U.S. to make reparations to Nicaragua for the harm suffered.
➢ The ICJ clarified that the decision was binding under Article 94 of the ICJ charter.21 Compliance:
➢ The USA did not agree to implement the ruling.22
➢ The case was brought to the UN Security Council by Nicaragua and did not happen through because of the U.S. veto power.
Ratio Decidendi:
Explanation of the Court’s Reasoning:
The reasoning in the ICJ’s decision was based on the persuasive force of the principles of customary international law and the stringent requirements surrounding self-defense under Article 51 of the UN Charter. Since the USA had derogated specific obligations from the jurisdiction of the ICJ through the reservations system, the court insisted that the rules that regulate the use of force and intervention have a binding effect irrespective of the international law regulation.23
In regard to this claim by the U.S., the Court held that there was neither an “armed attack” by Nicaragua on either El Salvador or any other state. In addition, there was also no valid request for assistance by El Salvador. The U.S. also failed to notify the UN Security Council.24
Legal Principles and Doctrines Applied:
1. Customary International
● The Court has reaffirmed that the prohibition on the use of force and the principle of non-intervention form part of customary international law binding on all states, irrespective of membership in Parties to the two Conventions.25
● This reinforced the autonomy of customary international law as a source of law under Article 38(1)(b) of the ICJ Statute.
2. Self Defense Doctrine
● The Court has clarified that self-defense must meet the following requirements:
● An actual military attack by a state.
● The request of the victim state to be aided.
● Notification to the United Nations Security Council.
● The US did not satisfy the three criteria, so their activities are illegal.26 3. Treaty Law Interaction:
The Court found that the U.S. breached the 1956 Friendship, Commerce and Navigation Treaty by disrupting peaceful commerce, showing that treaty obligations and customary law can operate concurrently.27
Important Precedents Cited :
● Corfu Channel Case (UK v. Albania, 1949): The ICJ reiterated the principle of sovereignty and non-interference and likened it to the claims of Nicaragua. 28
● Charter of the United Nations, Article 2(4) & Article 51: The Court extensively referred to these articles, interpreting them alongside the customary law.29
● The Court’s own jurisprudence :The Court revived a perception of continuity in customary norm application, stressing their obligatory character, even in regard to disputed treaty jurisdiction.
Conclusion:
The Nicaragua v. United States judgment remains a landmark in international law, affirming that the prohibition on the use of force and the principle of non‑intervention are binding rules of customary international law, independent of treaty obligations, and clarifying that self‑defense under Article 51 of the UN Charter requires a proven armed attack, a request by the victim state, and notification to the UN Security Council30. The Court’s rejection of the U.S. claim of collective self‑defense and its order for reparations underscored the authority of the ICJ, though the United States’ refusal to comply highlighted the limits of enforcement when powerful states resist international adjudication.31 Despite these challenges, the case continues to be cited in modern conflicts, including debates over Russia’s actions in Ukraine and U.S. interventions post‑2001, where its strict criteria for lawful self‑defense and emphasis on non‑intervention remain doctrinal anchors for scholars and practitioners.32
Reference(S):
● Case Concerning Military and Paramilitary Activities in and against Nicaragua (Nicaragua v United States of America) (Application Instituting Proceedings, 9 April 1984) [1986] ICJ Rep 14 https://icj-cij.org/case/70 accessed 22 December 2025.
● Case Concerning Military and Paramilitary Activities in and against Nicaragua (Jurisdiction and Admissibility) [1984] ICJ Rep 392 https://icj-cij.org/case/70 accessed 22 December 2025.
● Case Concerning Military and Paramilitary Activities in and against Nicaragua (Merits Judgment) [1986] ICJ Rep 14 https://icj-cij.org/case/70 accessed 22 December 2025.
● Corfu Channel Case (United Kingdom v Albania) (Merits Judgment) [1949] ICJ Rep 4 https://icj-cij.org/case/1 accessed 22 December 2025.
● Charter of the United Nations, arts 2(4), 51, 94 https://www.un.org/en/about-us/un-charter/full-text accessed 22 December 2025.
● Tom Ruys, ‘Armed Attack’ and Article 51 of the UN Charter (Cambridge University Press 2010).
● Mary Ellen O’Connell, ‘The Myth of Preemptive Self‑Defense’ (2002) ASIL Task Force Papers https://www.asil.org/insights/2002/09/myth-preemptive-self-defense accessed 22 December 2025.
● Wikipedia, ‘Nicaragua v. United States’ (Wikipedia, last updated 20 December 2025) https://en.wikipedia.org/wiki/Nicaragua_v._United_States accessed 22 December 2025.
1 Case Concerning Military and Paramilitary Activities in and against Nicaragua (Nicaragua v United States of America) (Judgment) [1986] ICJ Rep 14 <https://icj-cij.org/case/70> accessed 22 December 2025.
2 Richard A Falk, ‘The Nicaragua Case: A Comment on the Merits Phase’ (1987) 81 AJIL 160 <https://www.jstor.org/stable/2203019> accessed 22 December 2025.
3 Wikipedia, ‘Nicaragua v. United States’ (Wikipedia, last updated 20 December 2025)<https://en.wikipedia.org/wiki/Nicaragua_v._United_States> accessed 22 December 2025.
4 Case Concerning Military and Paramilitary Activities in and against Nicaragua (Nicaragua v United States of America) (Judgment) [1986] ICJ Rep 14 <https://icj-cij.org/case/70> accessed 22 December 2025.
5 Wikipedia, ‘Nicaragua v. United States’ (Wikipedia, last updated 20 December 2025)<https://en.wikipedia.org/wiki/Nicaragua_v._United_States> accessed 22 December 2025.
6 Richard A Falk, ‘The Nicaragua Case: A Comment on the Merits Phase’ (1987) 81 AJIL 160 <https://www.jstor.org/stable/2203019> accessed 22 December 2025.
7 Case Concerning Military and Paramilitary Activities in and against Nicaragua (Nicaragua v United States of America) (Judgment) [1986] ICJ Rep 14 <https://icj-cij.org/case/70> accessed 22 December 2025.
8ibid, paras 187–190.
9ibid, para 202.
10 ibid, paras 273–278
11ibid, para 292.
12 Case Concerning Military and Paramilitary Activities in and against Nicaragua (Jurisdiction and Admissibility) [1984] ICJ Rep 392 <https://icj-cij.org/case/70> accessed 22 December 2025.
13 ibid (Merits Judgment), paras 211–216.
14 Richard A Falk, ‘The Nicaragua Case: A Comment on the Merits Phase’ (1987) 81 American Journal of International Law 160 <https://www.jstor.org/stable/2203019> accessed 22 December 2025.
15 Case Concerning Military and Paramilitary Activities in and against Nicaragua (Jurisdiction and Admissibility) [1984] ICJ Rep 392 <https://icj-cij.org/case/70> accessed 22 December 2025.
16 Case Concerning Military and Paramilitary Activities in and against Nicaragua (Merits Judgment) [1986] ICJ Rep 14, paras 109–115 <https://icj-cij.org/case/70> accessed 22 December 2025.
17 ibid, paras 187–190.
18ibid, paras 202–205.
19 ibid, paras 273–278.
20ibid, paras 211–216
21 United Nations Charter, art 94 <https://www.un.org/en/about-us/un-charter/full-text> accessed 22 December 2025.
22 Wikipedia, ‘Nicaragua v. United States’ (Wikipedia, last updated 20 December 2025) <https://en.wikipedia.org/wiki/Nicaragua_v._United_States> accessed 22 December 2025.
23 Case Concerning Military and Paramilitary Activities in and against Nicaragua (Nicaragua v United States of America) (Merits Judgment) [1986] ICJ Rep 14, paras 172–176 <https://icj-cij.org/case/70> accessed 22 December 2025. 24 ibid, paras 211–216.
25ibid, paras 188–190.
26ibid, paras 194–195.
27 ibid, paras 273–278.
28 Corfu Channel Case (United Kingdom v Albania) (Merits Judgment) [1949] ICJ Rep 4, 35–36 <https://icj-cij.org/case/1> accessed 22 December 2025.
29 Charter of the United Nations, arts 2(4), 51 <https://www.un.org/en/about-us/un-charter/full-text> accessed 22 December 2025.
30 Case Concerning Military and Paramilitary Activities in and against Nicaragua (Nicaragua v United States of America) (Merits Judgment) [1986] ICJ Rep 14, paras 172–216 <https://icj-cij.org/case/70> accessed 22 December 2025.
31 ibid, para 292
32 Mary Ellen O’Connell, ‘The Myth of Preemptive Self‑Defense’ (2002) ASIL Task Force Papers <https://www.asil.org/insights/2002/09/myth-preemptive-self-defense> accessed 22 December 2025.
