Final answer:
NATO was established by the United States and its Western allies in response to the Cold War and Soviet aggression. Its main goal was to protect Europe and the West and provide collective defense.
Step-by-step explanation:
NATO, the North Atlantic Treaty Organization, was established by the United States and its Western allies after World War II in response to the emerging Cold War between East and West.
The main goal of NATO was to protect the interests of Europe and the West and provide collective defense against Soviet aggression. Member nations agreed that an attack on one of them would be considered an attack against all.
NATO initially included Western European nations and the United States, but it expanded to include countries from the East, such as Turkey, after the Cold War ended.