Article 5 of the North Atlantic Treaty, signed in 1949, is one of the most significant provisions of the alliance. It outlines the collective defense commitment of NATO members and is often referred to as the “attack on one is an attack on all” principle.

The article states that an attack on any NATO member is considered an attack on all members, and each member is committed to providing assistance to the attacked member. The assistance can include military force, economic aid, or any other support as agreed upon by the parties.

This provision has been invoked only once in NATO`s history, following the September 11, 2001 attacks in the United States. At the time, the U.S. claimed the attacks underlined the need for Article 5 to be activated. All NATO members agreed, and the alliance began its mission in Afghanistan, also known as the International Security Assistance Force (ISAF).

However, Article 5 does not automatically trigger a military response. It is up to each member to decide how they will assist the attacked member, and the response will depend on the circumstances and nature of the attack.

Additionally, Article 5 does not apply to attacks by non-NATO states or entities, such as terrorist groups. However, NATO has increasingly expanded its scope to address other security challenges beyond traditional defense, such as cyber-attacks, hybrid threats, and disinformation campaigns.

In conclusion, Article 5 is a cornerstone of NATO`s collective defense commitment and serves as a powerful deterrent against potential aggressors. While it may not have been invoked frequently, it remains an essential provision that underscores the importance of solidarity among NATO members in the face of security challenges.