The Dragaeran Empire.
The Galactic Republic.
The United Federation of Planets.
All worlds have countries, whether in fantasy, sci-fi, or alternate Earths. Some are real, and therefore don’t need much development beyond modifications to the genre or history. The culture is there, the cities, government, currency, etc. are all there, just potentially different. Others need to be built whole cloth, from the ground up.
As with the others in this mini-series, there are some minimum elements that I think we need to know. Other details can be added, of course, such as currencies, cultural inspiration, fashion, customs, economics, and languages, as desired.
Government—What kind of government is present? Is the government effective? What about a public government versus a shadow government? There are a wide variety of potential governments out there, so there’s no need to be limited to the typical fantasy empire or kingdom, nor for the sci-fi republic or empire. What major political factions exist?
Head of State—Who is in charge of the government? Is this individual a figurehead or does (s)he have actual authority and power? Or is this a council or similar group of people?
Geography—What’s the land like? Or planet, as the case may be? Who are the country’s neighbors? What relationships does it have with its neighbors? The internal geography can dictate transportation, communications, even sub-cultures and political divisions (both in terms of governing divisions and political factions).
Legislature—What body establishes the laws of the country? In some cases, this might be the head of state, with or without input from an advisory body. In other cases, there may be an entire legislative branch apart from the executive. Or the judicial branch may make the laws.
Law Enforcement—Who enforces the laws of the country? This is both who is on the streets as well as the judicial branches. Are there any special law enforcers? Or is law enforcement a scaled thing—e.g. local, regional, national?
Capital & Major Cities—The capital of the country is obviously a good thing to have in mind. But, there are also different types of capitals. What’s the political capital? Are there more than one (ex. at one point, the Roman Empire had two)? Is there a financial capital? Perhaps an academic capital? Or even a religious capital?
Ex. Washington, D.C. is the political capital of the U.S., but NYC is the financial and tourism capital. Riyadh is the political capital of Saudi Arabia, but Mecca is effectively a religious capital.
Religion—What religion(s) is/are known or represented in the country? Is there a state religion? Are there state gods? If there are multiple religions, how do they relate to each other? If there is a state religion, is it open to others or not? What are the faiths present like? Is there an unofficial state religion?
Ex. Officially, the U.S. has no state religion, unofficially Christianity is the state faith of the country; Denmark has a state religion, but it is very tolerant of other faiths; the UK has a state religion, led by the political head of state (who is a figurehead in both cases).
History— What has gone on in the country? When was it founded? How many leaders has it had? Was it involved in any major historical events? Has it changed over time? How? Were there any notable rulers (good or bad)?
Ex. Rome started as a kingdom, became a republic, then turned into an empire before becoming the Italian city-states, then a fascist ally of the Nazi regime, before finally settling as a democratic republic.