A country (or nation-state) is a self-governing entity that is generally smaller than a planetary government, and made up of smaller subnational entities (states or provinces), as is found in many instances on Earth.
The United Federation of Planets requires that planets have a unified government in order to be considered for Federation membership. However, planetary citizens often feel an attachment to their native region, which may have previously been a nation-state. (TNG: "Attached")
Countries of Earth
Template:Countries