Use of Force and Collective Security in International Law

Introduction – Use of Force and Collective Security

The use of force and collective security are pivotal concepts in Public International Law, addressing how states maintain peace, security, and order while respecting sovereignty. The UN Charter (1945) fundamentally transformed international law by prohibiting the unilateral use of force except in self-defense or when authorized by the UN Security Council.

Collective security is the principle that an attack against one member is considered an attack against all, obligating members to take collective action against aggression. These mechanisms aim to prevent war, regulate military action, and promote international cooperation.

---

1. Use of Force

Definition

The use of force refers to the employment of armed power by a state against another, including military operations, blockades, and threats of attack.

Legal Framework (UN Charter)

1. Article 2(4): Prohibits the threat or use of force against the territorial integrity or political independence of any state.
2. Article 51: Recognizes inherent right of individual or collective self-defense if an armed attack occurs.
3. Chapter VII (Articles 39–51): Empowers the UN Security Council to determine threats to peace and authorize measures, including use of force.

Exceptions to Prohibition

1. Self-Defense
   • Can be individual or collective.
   • Must be immediate, necessary, and proportional.
   • Case: Nicaragua v. United States (1986, ICJ) – US intervention violated international law; self-defense must be against actual armed attack.
2. UN Security Council Authorization
   • Article 42 allows military action to maintain or restore international peace.
   • Example: Korean War (1950–53) – UN-authorized military action against North Korea.
3. Consent of the State
   • Use of force is permissible if host state consents (e.g., coalition forces in Iraq post-2003).

Prohibited Uses of Force

• Aggression, invasion, occupation, bombardment, or military intervention without justification.
• Example: Russia’s invasion of Ukraine (2022) widely condemned as violation of Article 2(4).

---

2. Collective Security

Definition

Collective security is the concept where states agree that aggression against one is aggression against all, committing to collective response, including economic sanctions, military measures, or other actions to maintain international peace.

Legal Basis

• UN Charter, Chapter VII (Articles 39–51): Security Council determines threats and authorizes collective measures.
• Regional Collective Security Arrangements
  • NATO (North Atlantic Treaty, 1949) – Article 5: collective defense.
  • African Union: Peace and security protocols.

Principles of Collective Security

1. Inclusiveness: All member states share responsibility.
2. Automatic Response: Aggression triggers collective action.
3. Legitimacy: Actions must be authorized by an international organization like the UN.
4. Proportionality: Measures must be necessary and proportionate to restore peace.

---

3. Distinction Between Self-Defense and Collective Security

Aspect	Self-Defense	Collective Security
Initiator	State under attack	International organization (UN Security Council)
Basis	Article 51, UN Charter	Chapter VII, UN Charter
Scope	Individual or allied states	All member states collectively
Authorization	Automatic right	Requires Security Council approval
Example	Israel defending against attacks	UN response to Iraqi invasion of Kuwait (1990)

---

4. Case Law and Examples

1. Nicaragua v. United States (1986, ICJ)
   • US support for contras in Nicaragua violated Article 2(4); self-defense was not justified.
   • ICJ Case Link
2. Oil Platforms Case (Iran v. USA, 2003, ICJ)
   • US attack on Iranian oil platforms considered excessive; highlighted proportionality in self-defense.
   • ICJ Case Link
3. Korean War (1950)
   • First UN Security Council-authorized military intervention under collective security principles.
4. Gulf War (1990–1991)
   • UN Security Council authorized force against Iraq following invasion of Kuwait.

---

5. Contemporary Issues

1. Preemptive and Preventive Strikes
   • Debate over legality of strikes to prevent imminent threats (e.g., US drone strikes, Israel strikes on Iran).
2. Terrorism and Non-State Actors
   • Use of force against terrorist groups challenges traditional state-centric law.
3. Cyber Operations
   • Ambiguity in defining cyberattacks as “use of force” under Article 2(4).
4. Regional Conflicts and UN Limitations
   • Security Council veto power can impede collective action.
5. Humanitarian Interventions
   • NATO intervention in Kosovo (1999) raised debate on legality without Security Council approval.

---

6. Conclusion

The prohibition on the use of force and the principle of collective security are central to maintaining international peace and security. States must navigate self-defense rights, Security Council authorizations, and proportionality rules, while international organizations coordinate collective action. Understanding these principles is crucial for diplomats, international lawyers, and policymakers in addressing contemporary conflicts, terrorism, and humanitarian crises while respecting sovereignty and international law.

Also Read: International Organizations in Public International Law

Also Read: 7 Powerful Reasons Why Online Legal Internships Are Worth It for Law Students