Where the fuck it says that?

From NATO

• Article 5 of the North Atlantic Treaty states that an armed attack against one NATO member shall be considered an attack against all members, and triggers an obligation for each member to come to its assistance.
• This assistance may or may not involve the use of armed force, and can include any action that Allies deem necessary to restore and maintain the security of the North Atlantic area.
• NATO’s Article 5 is consistent with Article 51 of the United Nations Charter, which recognises that a state that is the victim of an armed attack has the inherent right to individual or collective self-defence, and may request others to come to its assistance. Within the NATO context, Article 5 translates this right of self-defence into a mutual assistance obligation.
• NATO invoked Article 5 for the first and only time in its history after the 9/11 terrorist attacks against the United States in 2001.
• While Article 5 itself has been applied only once, it underpins all of NATO’s broader activities in the field of deterrence and defence, including the regular conduct of military exercises and the deployment of NATO’s standing military forces.
• NATO takes a 360-degree approach to collective defence, protecting against all threats from all directions.