Answer :

Gibbs
NATO was initially formed as a system of collective defense to tie the member states to the mutual defense of the other states. This was created in response to the destruction of World War II and the United States and European countries desire to create a collective security agreement to counter what they perceived as the next threat the Soviet Union. 

interest in preventing future wars led to creation of the North Atlantic Treaty Organization (NATO) in 1949, which guaranteed the mutual defense of any member nation that was attacked by a non-member.