What is Article 5?
Article 5 of the NATO charter says that if one member nation is attacked, it is considered an attack on all of the member nations.
It reads:
“The Parties agree that an armed attack against one or more of them in Europe or North America shall be considered an attack against them all and consequently they agree that, if such an armed attack occurs, each of them, in exercise of the right of individual or collective self-defense recognized by Article 51 of the Charter of the United Nations, will assist the Party or Parties so attacked by taking forthwith, individually and in concert with the other Parties, such action as it deems necessary, including the use of armed force, to restore and maintain the security of the North Atlantic area.
“Any such armed attack and all measures taken as a result thereof shall immediately be reported to the Security Council. Such measures shall be terminated when the Security Council has taken the measures necessary to restore and maintain international peace and security.”
The principle has been a strong deterrent to attacks since it was signed in 1949. In fact, the only time it has been invoked is after the attacks on 9/11.
The alliance calls Article 5 the “principle of collective defense at the very heart of NATO’s founding treaty.”
What does it say?
The charter says that member countries will assist the attacked country “by taking forthwith, individually and in concert with the other Parties, such action as it deems necessary, including the use of armed force, to restore and maintain the security of the North Atlantic area.”
Who decides how countries will respond?
Each country decides how it will respond. The charter does not demand a specific response.