The following sentences contain blanks. Use the drop-down menus to complete each blank correctly. While some large multicountry [Dropdown 1] organizations promote economic and political goals, others form around military goals. For example, countries in Europe and North America formed [Dropdown 2] after World War II as a defense against the Soviet Union. In 1949, the first 12 member nations signed the [Dropdown 3] that binds them together and obligates them to defend one another in an invasion.