Coalition of the Willing

Concept Foreign Policy Preferred

Temporary group of States acting together on a specific military or political aim outside a standing alliance.

Independent referenceNot an official or legal definition
Sources citedSee the sources at the end of this page
Status Under reviewLast updated 11 October 2026
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Definition

In plain language

A coalition of the willing is a group of countries that choose to join a particular operation or effort, without being tied together by a permanent treaty or organisation.

Academic definition

The phrase became prominent in the early 2000s, notably for the US-led group of States that supported the 2003 invasion of Iraq without an explicit Security Council authorisation. Unlike alliances such as NATO, such coalitions have no standing decision-making structure, and participation can range from combat forces to political support. Their legitimacy depends on a legal basis such as a Council mandate, a request from the territorial State or collective self-defence under Article 51 of the UN Charter, and on political acceptance by other States.

Classification

Term type
Concept
Category
Foreign Policy
Subject field
Foreign Policy and Security
Subfield
Ad Hoc Coalitions
Difficulty level
Beginner
Grammatical category
noun phrase

Language variants

Alternative terms
  • ad hoc coalition
  • multinational coalition
Non-preferred terms
  • not_applicable
Abbreviations
  • CoW
Acronyms
  • not_applicable
Native terms
  • not_applicable
Transliteration
not_applicable
Pronunciation
not_applicable

Context

Legal effect: Political

Scope

Covers temporary voluntary groupings for specific operations; permanent alliances, collective security arrangements and UN-mandated multinational forces are different.

Legal context

No treaty regulates coalitions as such. Their actions must rest on a lawful basis under the UN Charter, such as Article 51 or a Chapter VII authorisation, and Article 53 requires Council authorisation for enforcement action by regional arrangements; ad hoc coalitions may be authorised by the Council.

Diplomatic context

Governments recruit partners through bilateral requests and public statements, and membership lists are often published to show broad support.

Institutional context

Led by one or more States, usually through a lead nation's headquarters, with no secretariat or formal institutional structure.

Historical context

The 1991 Gulf War coalition had Council authorisation, while the 2003 coalition for Iraq was widely criticised for lacking it, and later coalitions against ISIS were formed with host State consent.

Why it matters

Coalitions allow rapid action when institutions are deadlocked, but they can raise questions about legality, burden sharing and long-term accountability.

Usage

Register: Media

Usage note

Put the phrase in quotation marks at first use when referring to the 2003 coalition; it is not a legal term.

Example

The government joined a coalition of the willing to support the evacuation mission.

Example scenario

State A, unable to obtain a Council resolution, assembles ten partners to deploy a stabilisation force at the host State's request. Each partner decides separately what to contribute, and the legal basis is the host State's consent.

Common misuse

Treating a coalition of the willing as an international organisation or as automatically legal because many States participate.

Not to be confused with

  • Military alliance
  • Collective security system
  • UN peacekeeping operation
  • Multinational force

Sources

  1. Charter of the United Nations (1945), United Nations, Articles 51 and 53. un.org
  2. Official definition. not_found_in_source
  3. Treaty reference. un.org
  4. Gray, International Law and the Use of Force. not_found_in_source
  5. not_found_in_source. not_found_in_source

Source type: Treaty. Source reliability: Primary.

This entry is an independent reference definition, not an official or legally binding text. Where an official definition exists, it is linked above and is authoritative. Read our methodology.

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