Article 5 (collective defense)

Article 5 of the NATO treaty establishes the principle of collective defense, meaning that an attack on one member is considered an attack on all. If a member country is attacked, the other members are committed to respond, potentially including military action, to help defend that country. This creates a sense of mutual security and deterrence, encouraging members to unite against threats and ensuring that an aggressor cannot easily target one country without facing a coordinated response from the entire alliance.