Consolidated version of the Treaty on European Union

Article 42 U.K. (ex Article 17 TEU)

1. The common security and defence policy shall be an integral part of the common foreign and security policy. It shall provide the Union with an operational capacity drawing on civilian and military assets. The Union may use them on missions outside the Union for peace-keeping, conflict prevention and strengthening international security in accordance with the principles of the United Nations Charter. The performance of these tasks shall be undertaken using capabilities provided by the Member States.

2. The common security and defence policy shall include the progressive framing of a common Union defence policy. This will lead to a common defence, when the European Council, acting unanimously, so decides. It shall in that case recommend to the Member States the adoption of such a decision in accordance with their respective constitutional requirements.

The policy of the Union in accordance with this Section shall not prejudice the specific character of the security and defence policy of certain Member States and shall respect the obligations of certain Member States, which see their common defence realised in the North Atlantic Treaty Organisation (NATO), under the North Atlantic Treaty and be compatible with the common security and defence policy established within that framework.

3. Member States shall make civilian and military capabilities available to the Union for the implementation of the common security and defence policy, to contribute to the objectives defined by the Council. Those Member States which together establish multinational forces may also make them available to the common security and defence policy.

Member States shall undertake progressively to improve their military capabilities. The Agency in the field of defence capabilities development, research, acquisition and armaments (hereinafter referred to as ‘the European Defence Agency’) shall identify operational requirements, shall promote measures to satisfy those requirements, shall contribute to identifying and, where appropriate, implementing any measure needed to strengthen the industrial and technological base of the defence sector, shall participate in defining a European capabilities and armaments policy, and shall assist the Council in evaluating the improvement of military capabilities.

4. Decisions relating to the common security and defence policy, including those initiating a mission as referred to in this Article, shall be adopted by the Council acting unanimously on a proposal from the High Representative of the Union for Foreign Affairs and Security Policy or an initiative from a Member State. The High Representative may propose the use of both national resources and Union instruments, together with the Commission where appropriate.

5. The Council may entrust the execution of a task, within the Union framework, to a group of Member States in order to protect the Union's values and serve its interests. The execution of such a task shall be governed by Article 44.

6. Those Member States whose military capabilities fulfil higher criteria and which have made more binding commitments to one another in this area with a view to the most demanding missions shall establish permanent structured cooperation within the Union framework. Such cooperation shall be governed by Article 46. It shall not affect the provisions of Article 43.

7. If a Member State is the victim of armed aggression on its territory, the other Member States shall have towards it an obligation of aid and assistance by all the means in their power, in accordance with Article 51 of the United Nations Charter. This shall not prejudice the specific character of the security and defence policy of certain Member States.

Commitments and cooperation in this area shall be consistent with commitments under the North Atlantic Treaty Organisation, which, for those States which are members of it, remains the foundation of their collective defence and the forum for its implementation.