Advisory Opinions of the ICJ

Introduction

An advisory opinion is a legal opinion given by the International Court of Justice (ICJ) on a legal question referred to it by an authorised United Nations organ or specialised agency.

Unlike contentious proceedings, an advisory proceeding does not ordinarily involve two States litigating against each other for a binding judgment.

The advisory jurisdiction of the ICJ is principally governed by Article 96 of the UN Charter and Articles 65–68 of the ICJ Statute.

The basic idea is:

Authorised UN organ / specialised agency

↓

Legal question

↓

Request to ICJ

↓

Written and oral proceedings

↓

ICJ Advisory Opinion

↓

Legal guidance and clarification

Meaning of Advisory Opinion

An advisory opinion is the formal opinion of the ICJ on a legal question referred to it by an authorised body.

It is called “advisory” because the Court is not deciding a contentious dispute between States in the same way that it does in its contentious jurisdiction.

However, “advisory” does not mean that the opinion is legally insignificant.

ICJ advisory opinions can have substantial importance in:

• interpretation of international law;
• clarification of legal obligations;
• development of international legal principles;
• United Nations practice;
• international dispute settlement;
• determination of the legality of conduct.

Legal Basis

Article 96 of the UN Charter

Article 96 establishes who may request advisory opinions.

The General Assembly and Security Council may request the ICJ to give an advisory opinion on any legal question.

Other organs of the UN and specialised agencies may also request advisory opinions on legal questions arising within the scope of their activities, provided they are authorised to do so.

Article 65 of the ICJ Statute

Article 65 provides the principal statutory basis for the Court’s advisory jurisdiction.

The Court may give an advisory opinion on any legal question at the request of whatever body may be authorised by or in accordance with the UN Charter to make such a request.

Therefore:

Article 96 UN Charter → Who may request

Article 65 ICJ Statute → Court’s advisory jurisdiction

Who Can Request an Advisory Opinion?

General Assembly

The General Assembly can request an advisory opinion on any legal question.

Security Council

The Security Council can also request an advisory opinion on any legal question.

Other UN Organs

Other UN organs may request an opinion where:

• they are authorised to do so; and
• the question falls within the scope of their activities.

Specialised Agencies

Specialised agencies may request advisory opinions when:

• they are authorised under the applicable framework; and
• the question arises within the scope of their activities.

Who Cannot Directly Request an Advisory Opinion?

Private individuals, corporations, NGOs and ordinary private organisations cannot directly request an advisory opinion from the ICJ.

The advisory jurisdiction operates through the authorised institutional mechanisms of the UN system.

Legal Question Requirement

The question referred to the ICJ must be a legal question.

A question may concern:

• interpretation of a treaty;
• existence of an international legal obligation;
• legality of conduct;
• consequences of breach;
• application of international law.

The fact that a question has political implications does not automatically prevent it from being a legal question.

Political Questions

Many advisory proceedings involve highly political circumstances.

The ICJ has repeatedly recognised that the political character or political consequences of a question do not automatically deprive the Court of jurisdiction.

The essential issue is whether the question submitted is legal in character.

Important Principle

Political consequences ≠ necessarily political question

A question can have major political implications while still being a legal question capable of receiving an advisory opinion.

Discretion of the ICJ

Even where the Court has jurisdiction to give an advisory opinion, it is not necessarily required to answer every request.

Article 65 uses the language “may give” an advisory opinion.

The Court therefore has a degree of discretion.

However, the Court has generally emphasised that it should not refuse a properly requested advisory opinion without compelling reasons.

Consent of States

A major difference between contentious and advisory jurisdiction concerns State consent.

In contentious proceedings, the Court’s jurisdiction over States is based on their consent.

In advisory proceedings, the Court does not require the consent of every State potentially affected in the same way.

This is because the advisory opinion is formally requested by an authorised international institution rather than being a judgment imposed upon a State in a contentious case.

Western Sahara Advisory Opinion

Western Sahara (1975)

The ICJ was asked questions concerning the legal status of Western Sahara.

The Court examined historical legal relationships and concluded that there were certain legal ties but that they did not establish territorial sovereignty of Morocco or Mauritania over Western Sahara.

The opinion is an important example of the Court addressing a politically sensitive question through legal analysis.

Reparation for Injuries Advisory Opinion

Reparation for Injuries Suffered in the Service of the United Nations (1949)

This is one of the most important advisory opinions in ICJ history.

The question concerned whether the United Nations possessed international legal personality and whether it could bring an international claim for injury caused to its agent.

The Court recognised the international legal personality of the United Nations and its capacity to bring an international claim.

Importance

The opinion significantly contributed to the development of the law concerning:

• international organisations;
• international legal personality;
• implied powers;
• international claims.

Reservations to the Genocide Convention

Reservations to the Convention on the Prevention and Punishment of the Crime of Genocide (1951)

The Court considered the permissibility of reservations to the Genocide Convention.

The opinion contributed to the development of the modern law concerning:

• treaty reservations;
• compatibility of reservations with the object and purpose of treaties;
• participation in multilateral conventions.

Namibia Advisory Opinion

Legal Consequences for States of the Continued Presence of South Africa in Namibia (1971)

The Court considered the legal consequences of South Africa’s continued presence in Namibia.

The opinion addressed:

• legality of South Africa’s presence;
• obligations of States;
• consequences for the international community.

It is an important authority concerning the legal consequences of unlawful territorial situations.

Nuclear Weapons Advisory Opinion

Legality of the Threat or Use of Nuclear Weapons (1996)

The Court considered whether the threat or use of nuclear weapons was permitted under international law.

It examined:

• international humanitarian law;
• UN Charter rules;
• self-defence;
• environmental considerations;
• international obligations concerning nuclear weapons.

The opinion is particularly important because the Court concluded that it could not definitively determine, in the extreme circumstance of self-defence where the very survival of a State would be at stake, whether the threat or use of nuclear weapons would be lawful or unlawful.

Wall Advisory Opinion

Legal Consequences of the Construction of a Wall in the Occupied Palestinian Territory (2004)

The Court considered the legal consequences of construction of the wall in the occupied Palestinian territory.

The opinion addressed:

• international humanitarian law;
• human rights law;
• self-determination;
• obligations of States;
• legal consequences of violations.

It is one of the most frequently cited modern ICJ advisory opinions.

Kosovo Advisory Opinion

Accordance with International Law of the Unilateral Declaration of Independence in Respect of Kosovo (2010)

The ICJ was asked whether the unilateral declaration of independence by Kosovo was in accordance with international law.

The Court concluded that the declaration of independence did not violate general international law.

The opinion is important for the relationship between:

• unilateral declarations;
• territorial status;
• self-determination;
• international law.

Chagos Advisory Opinion

Legal Consequences of the Separation of the Chagos Archipelago from Mauritius in 1965 (2019)

The Court considered the legality and consequences of the separation of the Chagos Archipelago from Mauritius.

The opinion addressed:

• self-determination;
• decolonisation;
• territorial administration;
• obligations of the international community.

The Court concluded that the decolonisation of Mauritius had not been lawfully completed and identified legal consequences for the United Kingdom’s continued administration of the Chagos Archipelago.

Occupied Palestinian Territory Advisory Opinion

Legal Consequences arising from the Policies and Practices of Israel in the Occupied Palestinian Territory, including East Jerusalem (2024)

The ICJ issued an advisory opinion addressing the legal consequences arising from policies and practices in the occupied Palestinian territory.

The Court examined questions involving:

• occupation;
• self-determination;
• annexation;
• international humanitarian law;
• human rights law;
• obligations of States and international organisations.

The opinion illustrates the continuing importance of the ICJ’s advisory jurisdiction in major questions of international law.

Procedure for an Advisory Opinion

The general process can be understood as:

Authorised body

↓

Formulates legal question

↓

Request transmitted to ICJ

↓

Court identifies States and organisations that may provide information

↓

Written statements

↓

Oral proceedings, where appropriate

↓

Judges deliberate

↓

Advisory Opinion delivered publicly

Written and Oral Proceedings

The Court may invite:

• States;
• international organisations;
• other relevant participants

to provide written observations and participate in oral proceedings where appropriate.

This allows the Court to receive different legal perspectives before giving its opinion.

Article 66 of the ICJ Statute

Article 66 establishes important procedural requirements concerning advisory opinions.

The Court’s Registrar communicates the request and invites relevant States and organisations to provide information.

The Court may conduct written and oral proceedings where appropriate.

Article 67

Article 67 provides for the public delivery of the advisory opinion.

The opinion is delivered in open court.

Article 68

Article 68 provides that, in exercising its advisory functions, the Court will be guided by the provisions of the Statute concerning contentious cases to the extent that it considers them applicable.

Thus, the advisory procedure has its own framework but can draw upon the Court’s general procedural rules.

Are Advisory Opinions Binding?

As a general rule, ICJ advisory opinions are not legally binding in the same manner as judgments in contentious cases.

This is one of the most important distinctions in ICJ law.

Contentious Judgment

Binding on the parties

under Article 59

Advisory Opinion

Generally not binding

But an advisory opinion may possess substantial:

• legal authority;
• persuasive force;
• interpretive value;
• normative significance.

Advisory Opinions and Article 59

Article 59 states that the Court’s decision has no binding force except between the parties and in respect of that particular case.

An advisory opinion is not a contentious judgment between parties in the same sense.

Therefore, it should not simply be treated as a universally binding judicial decision.

Advisory Opinion Can Have Binding Consequences?

Although the opinion itself is generally non-binding, the legal instrument under which it is requested may attach particular legal consequences to it.

For example, a treaty, constitution or institutional arrangement may provide for consequences following an advisory opinion.

Therefore:

General rule → non-binding

but

Specific legal framework → may create particular consequences

Advisory Opinion vs Contentious Judgment

Advisory Opinion	Contentious Judgment
Advisory jurisdiction	Contentious jurisdiction
Legal question referred by authorised body	Dispute between States
Articles 65–68 ICJ Statute	Articles 34–38 and relevant Statute provisions
Article 96 UN Charter	Article 94 UN Charter relevant to compliance
Generally non-binding	Binding between parties
No ordinary “parties” in same sense	States are parties
State consent not required in same manner	Consent is fundamental
Gives legal opinion	Determines dispute
Can have major persuasive authority	Legally binding on parties

Advisory Opinion vs ICJ Judgment

The distinction can be remembered as:

Judgment

→ “Who is legally entitled?”

Advisory Opinion

→ “What does international law say?”

This is a simplified way of understanding the difference for examination purposes.

Advisory Jurisdiction and International Organisations

Advisory opinions have played a major role in defining the powers and legal personality of international organisations.

The Reparation for Injuries opinion is particularly important because it recognised the international legal personality and capacity of the United Nations.

Advisory Opinions and Development of International Law

Although not generally binding, advisory opinions can contribute significantly to international law.

They may:

• clarify existing customary rules;
• interpret treaties;
• identify State obligations;
• explain consequences of unlawful conduct;
• influence State practice;
• guide international organisations;
• shape later judicial decisions.

Advisory Opinions and Customary International Law

An advisory opinion does not itself automatically create a customary international law rule.

However, the Court’s reasoning may:

• identify an existing customary rule;
• clarify its content;
• contribute to its development.

The wider legal effect depends upon the underlying international law, not merely upon the advisory status of the opinion.

Advisory Opinions and Political Questions

The ICJ has generally been willing to consider questions with significant political dimensions when they are properly framed as legal questions.

The Wall, Kosovo, Chagos, and Nuclear Weapons opinions demonstrate this.

The presence of political controversy does not by itself eliminate the Court’s advisory jurisdiction.

Advisory Opinions and Judicial Propriety

The Court may consider whether giving an advisory opinion would be consistent with its judicial function.

The Court has generally approached refusal cautiously because advisory opinions can serve important purposes within the UN system.

The Court’s discretion is therefore real but not unlimited in practical terms.

Important Cases

Reparation for Injuries (1949)

Principle: International legal personality of the United Nations.

Reservations to the Genocide Convention (1951)

Principle: Reservations to multilateral treaties and object-and-purpose approach.

Namibia (1971)

Principle: Legal consequences of an unlawful international situation.

Western Sahara (1975)

Principle: Legal status and territorial claims in the context of decolonisation.

Nuclear Weapons (1996)

Principle: Relationship between nuclear weapons, self-defence and international humanitarian law.

Wall (2004)

Principle: Legal consequences of violations involving occupation, self-determination and humanitarian/human rights law.

Kosovo (2010)

Principle: International law and unilateral declaration of independence.

Chagos (2019)

Principle: Self-determination and completion of decolonisation.

Occupied Palestinian Territory (2024)

Principle: Legal consequences of policies and practices in occupied territory and obligations arising under international law.

Key Articles

Provision	Subject
UN Charter Article 96	Authority to request advisory opinions
ICJ Statute Article 65	Advisory jurisdiction
Article 66	Procedure and communications
Article 67	Public delivery
Article 68	Application of procedural provisions
Article 38	Sources of international law
Article 59	Binding force of contentious judgments
Article 94 UN Charter	Compliance with ICJ decisions

Complete Flowchart

Legal question

↓

Authorised UN body / specialised agency

↓

Request to ICJ

↓

Article 96 UN Charter + Article 65 ICJ Statute

↓

Court examines jurisdiction and discretion

↓

Written proceedings

↓

Oral proceedings, where appropriate

↓

Court’s deliberation

↓

Advisory Opinion

↓

Generally non-binding

↓

Major legal + persuasive significance

Quick Revision

Question	Answer
Meaning	ICJ opinion on a legal question
Main provision	Article 65 ICJ Statute
UN Charter provision	Article 96
General Assembly	Can request on any legal question
Security Council	Can request on any legal question
Other UN organs/agencies	Subject to authorisation and scope of activities
Individuals	Cannot directly request
Question	Must be legal
State consent	Not required in same manner as contentious jurisdiction
Binding?	Generally no
Legal importance	Very high
Procedure	Articles 65–68
Public delivery	Article 67
Key case	Reparation for Injuries
Other cases	Namibia, Western Sahara, Nuclear Weapons, Wall, Kosovo, Chagos
Modern example	Occupied Palestinian Territory (2024)

Key Exam Points

• Advisory opinions are governed principally by Article 96 of the UN Charter and Articles 65–68 of the ICJ Statute.
• The General Assembly and Security Council may request advisory opinions on any legal question.
• Other UN organs and specialised agencies may request opinions subject to the applicable authorisation and their field of activities.
• Individuals, private organisations and States acting alone cannot directly request an advisory opinion.
• The question submitted must be legal in character.
• Political implications do not automatically prevent the Court from answering a legal question.
• The Court possesses discretion in exercising its advisory jurisdiction.
• The consent of potentially affected States is not required in the same manner as in contentious jurisdiction.
• Advisory opinions are generally non-binding.
• Their non-binding character does not make them legally unimportant.
• Advisory opinions can significantly influence the interpretation and development of international law.
• Reparation for Injuries (1949) recognised the international legal personality of the United Nations.
• Namibia (1971) addressed the legal consequences of an unlawful international situation.
• Western Sahara (1975) addressed territorial status and decolonisation.
• Nuclear Weapons (1996) examined nuclear weapons under international law.
• Wall (2004) addressed occupation, self-determination and international humanitarian/human rights law.
• Kosovo (2010) considered the legality under international law of a unilateral declaration of independence.
• Chagos (2019) addressed self-determination and decolonisation.
• Occupied Palestinian Territory (2024) addressed the legal consequences of policies and practices in occupied territory.
• An advisory opinion should not be confused with a contentious judgment, which is binding between the parties under Article 59.

Conclusion

The advisory jurisdiction of the ICJ provides an important mechanism through which the United Nations system can obtain authoritative judicial guidance on questions of international law. Unlike contentious jurisdiction, it does not primarily resolve a dispute between States through a binding judgment.

The central provisions are Article 96 of the UN Charter and Articles 65–68 of the ICJ Statute. The General Assembly and Security Council possess broad authority to request advisory opinions, while other authorised UN organs and specialised agencies have more limited powers.

Although advisory opinions are generally non-binding, their importance extends far beyond their formal status. Through opinions such as Reparation for Injuries, Namibia, Western Sahara, Nuclear Weapons, Wall, Kosovo and Chagos, the ICJ has played a major role in clarifying and developing international law.

For examination purposes, remember:

Article 96 UN Charter → Who can request

Article 65 ICJ Statute → Advisory jurisdiction

Article 66 → Procedure

Article 67 → Public delivery

Article 68 → Applicable procedural provisions

Advisory Opinion → Generally non-binding

Contentious Judgment → Binding between parties under Article 59