Fantasy authors are rarely as meticulous in their worldbuilding as JRR Tolkien. Thus fantasy countries are often borrowed from the history books, if not the current world map. For example, GRR Martin's Westeros is just the UK with some rotation.
"Overlord" by Kugane Maruyama is a fantasy isekai in which an introverted salaryman is reincarnated as a lich commanding a legion of monsters, whom he leads to genocide a country full of White Christians.
Nazarick is obviously revanchist Imperial Japan. Maruyama's resentment against Europeans is understandable, considering the USA's long history of dominating Japan.
In Overlord, some countries are majority human, whereas others are majority monster, e.g. minotaurs. The human countries often represent White countries. I can recognize a few just from their map and wiki descriptions:
- Re-Estize Kingdom = Australia, weak due to dependence on natural barriers, corrupt and divided, first White target for Japanese conquest
- Slane Theocracy = USA, aggressive high-tech theocratic republic with a racist history
- Baharuth Empire = Russia, with bloody tsar purging nobility.
- Roble Holy Kingdom = United Kingdom, complete with Hadrian's Wall and a queen. Abelion Hills = white cliffs of Dover = perfidious Albion = England.
The nearby lizard people are the Southeast Asians of Oceania whom Imperial Japan easily conquered.
I can't find China, probably because China is about to conquer Japan, and the author would prefer to reminisce about the glory days instead. It might be one or more of the "dragon" countries.
What others can you find?
Discussion
Why Australia?
- Proposed Japanese invasion of Australia during World War II | Wikipedia
- 1942 - An Overview of the Battle for Australia | ANZAC Day Commemoration Committee
The Japanese author might regard Australia as corrupt because it was founded by banished criminals and has much more murder than Japan. Or he might be criticizing the corruption and hypocrisy of the Anglosphere West in general, with Australia being merely the nearest example thereof. Japanese tend to be dismissive of Australia.
I explained the above to the r/Overlord subreddit. They didn't like it, and grew angry.
Overlord doesn't seem to be aimed at an audience with much awareness of geopolitics. Otherwise they might grow appalled at a Japanese man unsubtly glorifying the atrocities of the Japanese Imperial Army.
Having watched the anime and read parts of the ligh novel, no, this seems a self insert of geopolitics where it wasn't to begin with.
The important parts left out of this summary is that Momonga (who after the transfer takes the name of his guild of Ainz Ooal Gown) when he first started playing the game was picked on a lot in game because he chose a non-human character. He was saved by Lord Touch me (the best fighter ever as his name was a taunt) and together with other non human characters they would form a guild where they would role-play being the villains. The requirements of the guild were non human characters and be a functioning member of society so you had stakes in the real world that you had to sacrifice to play.
Over time members left one by one leaving Momonga by himself that when the game came to an end, he was left with the guild and NPCs they all created. After the transfer, these NPCs actually 'wake up' and not only can act independently, but remember EVERYTHING of when it was a game and worship their creator players as divine beings as gods for breathing live into them. They hold Momonga in highest esteem because 'he stayed with them and never left' so feel indebted to him. Momonga though is paranoid and cautious so believes if he doesn't live up to the ruthless reputation he had when it was a game, they'll abandon him (which the author actually implies they wouldn't because they are that devoted to him) especially how before transfer he messed with Albedo's setting to say she is in love with Momonga. He also no longer feels anything as thanks to his non human body, his emotions both good and bad are greatly suppressed.
So let's combine this context with the actual countries in the series: Baharuth Empire: main force is professional soldiers, constantly battling Re-Estize Kingdom for territory, they initially find one of Momonga's dungeons and decide to send a disposable team of adventures to investigate. This becomes one of the most BRUTAL chapters in the story when it turns out to be a trap to test Nazarick's defenses and as an excuse to interact with the Empire under the pretense of compensation for the 'invasion'. The Empire tries to feign an alliance in the hopes that if they are brought to the world's attention, they could form a worldwide alliance to stop them.
This plan fails thanks to some 'baby goats' and after another failed attempt to gain the favour of Slane Theocracy, they appeal for vassalation under Nazarick.
This doesn't look like Russia, if anything it's the dying days of the roman empire but this story is not as simple as 'it's imperial Japan' because it's taking the classic fantasy setting and instead of the transferee being sent to save them from a great evil, they CAN be the great evil as there are many times Momonga saves people to use them but they end up revering him as a device being too (see the fingers).
So in conclusion, it's your theory is WAY off the mark, it doesn't 'glorify white genocide or genocide of Christians' it's about the consequences of paranoia, the role playing to a schizophrenic level of Momonga and the NPCS who have an inbuilt good or evil karma interacting in a world when in game they were treated as monsters by humans.
Go look at all of op's posts. They are just GPT ramblings.
tl;dr: "It can't be the author's hidden motivation because he provided an explicit plot explanation."
One should hope he did. Literary critics only complain when the plot is overly contrived. The ability to look below the surface of a text to discern author motive is a skill that requires both talent and training, and is tested on standardized admissions tests.
Regularly raiding from the steppe is indeed a Russian trait, from the European perspective. Moving Nippon/Nazarick from the ocean to the steppe requires some changes to the map, allowing Russia to invade Re-Estize/Australia regularly. Australia has little footprint in Japan's literary imagination, and none in medieval times, leaving it a composite. Perhaps Poland is another influence, or another oft-overrun Slavic country.
This post was mainly to check whether I was missing other country correspondences. At some point I may buckle down and prove the parts of my thesis that fans of Overlord find unintuitive. I certainly have the notes accumulated.
No one is interested in your schizo posting
You're applying our world geopolitics to a fantasy world that has it's own geopolitical structure thanks to a new resource: magic
This is why the Slane Theocracy is such a big player but then immediately is on the backfoot because of Ainz's arrival. They had to use a world level item just against ONE of his subordinates and it only managed to make her stuck in a self defence mode. Ainz isn't interested in genocide and by consequence neither is his subordinates, they are just looking for the quicker results whether that involves making deals or purging a bunch of 'insects'.
Ainz still has a softer shown by how he added a certain little sister to 'the list' and there are NPCs with good karma that try to save people or just not needlessly kill when it isn't required. Many of the worst atrocities committed by Ainz and Nazarick is because his enemies (mostly humans) apply their politics to him as a means of controlling or understanding him when his power OVERRIDES those requirements (such as after his talk with a prince, he was actually close to calling it off but because the nobles killed and betrayed the prince to save their own skin and show their allegiance to Ainz, he wiped the capital off the face off the earth).
TLDR: the whole point of Overlord shows the folly of applying politics to a being with ABSOLUTE power.