In the event of an armed attack in Europe on one or several states that are signatories of the treaty by any state or group of states, each state that is a party to this treaty shall, in the exercise of the right to individual or collective self-defence in accordance with Article 51 of the Charter of the United Nations Organisation, render the state or states so attacked immediate assistance, individually and in agreement with other states that are parties to this treaty, by all the means it may consider necessary, including the use of armed force. The states that are parties to this treaty shall immediately take council among themselves concerning the necessary joint measures to be adopted for the purpose of restoring and upholding international peace and security.

In accordance with the principles of the Charter of the United Nations Organisation, the Security Council shall be advised of the measures taken on the basis of the present article. These measures shall be stopped as soon as the Security Council has taken the necessary measures for restoring and upholding international peace and security-.