North Atlantic Treaty Organization

This is the principle of collective defence, which is enshrined in Article 5 of the Washington Treaty. So far, Article 5 has been invoked once - in response to the 9/11 terrorist attacks in the United States in 2001. NATO is an alliance of countries from Europe and North America. It provides a unique link between these two continents, enabling them to consult and cooperate in the field of defence and security, and conduct multinational crisis-management operations together. Kjene