Country spirits is the term Humon uses for the characters of Scandinavia and the World. Each one is an amalgamation of many aspects of the country, starting with a stereotypical view of the citizens and their culture and then adding political developments, current events, governmental structures, geological and geographic features, and even events surrounding an individual citizen as needed, with the whole thing wrapped in a shirt bearing the design of the country's flag.
Not all of the country spirits represent countries per se--some represent provinces or states (Scania, New South Wales), ethnic or linguistic minorities (Kven, FennoSwede), multinational organizations (King Europe), or existing countries as they were under previous governments (Nazi Germany). What all these things have in common is that they are political entities, and it is easy to re-imagine their real-world dealings, in the modern day and throughout history, as the wacky antics of a cast of sit-com style characters.
Fans of the series love to speculate about country spirits as yet unrevealed, and come up with their own designs and personalities for them based on the patterns established in the comics and their own understandings of the country (or state, province, etc.) in question.