Downplayed: The Troperian Empire is a chain of supermarkets.
Justified: The Troperian Empire is sitting on a cache of Applied Phlebotinum that allowed it to become the most militarily powerful country in the world.
Troperian Alliance is a loose coalition of states and factions fighting for liberation of their lands.
The Troperian Empire is fighting for the survival of civilization against the evil Barbarian Tribe.
Troperia is a tiny city-state that would be crushed instantly by just about any other nation.
"Troperian Empire" is merely an Artifact Title, and the country of Troperia isn't nearly as huge and aggressive as it used to be.
Alternatively, "Troperian Empire" is a GOOD empire truly caring for the welfare of its citizens and deliberately avoid using iron fisted rules. It's just the La Résistance who's spreading propaganda about how 'bad' Troperian Empire is based on the common fallacy/perception of 'Empire = Obviously Evil'.
The Troperian Commonwealth has the trappings of an Empire (An Empress, nobility, a strong and powerful military). However, its govern by a democratically elected parliament, and member states not only have autonomy but volunteered to unite under the Empress. Its goals are peace and prosperity.
The Troperian Empire has all the bark about being The Empire, but its military and territory are no greater than those of their neighbors.
However, it still has economic influence left over from its days of conquest, so it's still one of the major players in the world.
The Empire only appears to be good, but it is unbelievably corrupt, and is slowly mind raping its citizens into obedience. The Empire's humanitarian nature is merely a front for the evil it commits behind the scenes. La Résistance are just run by people in on the secret, but because they can't conclusively prove the Empire's evil (or worse, they can, but it benefits La Résistance as well as the Empire to keep the truth hidden), they look like heartless terrorists blowing up malls For the Evulz (or even worse, they are terrorists for the evulz and the whole thing is an Evil vs. Evil situation.)
The Commonwealth is an oligarchy, with the democratic trappings being just that: trappings. The Empress is a succubus that brainwashed the nation's democratic leaders into serving her so she can rule the nation and eventually sacrifice it to Satan to become an Archdevil
An asteroid strikes the world of the Troperian Empire, and pieces hit every state on that planet...except Troperian. Payback is a bitch, yes?
Parodied: Troperia is a Micro Monarchy, yet the government still insists that everyone calls it "The Glorious Troperian Empire".
Zig Zagged: The conflict runs on Grey and Gray Morality, so it's not entirely obvious which of the several Empires in the story is the Empire.
Averted: A standard space opera / fantasy tale lacks any Empire, evil or otherwise.
Enforced: The writer wanted a story with a singular, unified threat to everything the heroes hold dear, so the Evil Empire fits the bill perfectly.
Lampshaded: "So, this is a fairly standard case: an evil empire bent on world conquest."
Invoked: A character decides that the world / galaxy needs order. Deciding that the only way he can accomplish this, he works to create an Empire.
Exploited: Realizing that the Empire is rising, an industrialist gets in good with the future Emperor. Since the Empire needs a lot of war material for their conquests, the businessman gets rich and powerful.
During the formative process of, well, The Empire, the decision is made to actively avoid calling it an Empire, to avoid provoking the obviousreactions.
The hero attempts to prevent his nation from becoming the Empire, seeing the danger it poses to peace.
Discussed: "So you're gonna create a massive global superpower that enforces your will with an iron fist? What're you gonna call it, The Empire?"
Conversed: "Oh c'mon, everyone knows that any nation calling itself The Empire is evil and bent on world domination."
Implied: The Supremacy conquers other worlds, consist of millions of star systems, and commands a powerful military. Their colors are red and black, employ mean looking weapons, and Sigil Spam is everywhere.
The work takes a closer look at the Troperian Empire, and shows all the trouble the Emperor has to get through to keep it in one piece: keeping down national tensions, separatism, political corruption, bureaucratic inefficiency, the list goes on and on.
Reconstructed: After the above troubles threaten to tear the Empire apart, The Emperor initiates sweeping reforms, shaking up the entire system, causing a period of upheaval and social unrest but ultimately culminating in a government that runs smoother and more efficiently than ever before, while keeping the masses happy with Bread and Circuses rather than brutal oppression.