The military alliance formed in 1949 is called "NATO," which stands for the North Atlantic Treaty Organization. Established in response to the geopolitical tensions following World War II, NATO was created to ensure mutual defense among its member countries in the event of an attack. The founding members primarily included the United States, Canada, and several Western European nations. Over the years, NATO has expanded to include many more countries and plays a crucial role in international security, collective defense, and political cooperation in addressing global challenges and conflicts.