[potatoyogurt]

Did you read his link? It directly addresses your point. I will summarize and add some context, since I don't know if you read Russian. The word мир in Russian has two meanings, "peace" and something that is translated in different contexts more like "the world" or "society." These were once different words with different spellings, but during the Soviet Union, authorities decided that some letters had to be purged because they were naughty, so orthographic reforms were carried out that standardized some spellings and eliminated a few letters. So the previously distinguishable words "мир"(peace) and мір (the world/society) became orthographically indistinguishable. However, since Tolstoy published prior to the Soviet Union, you can tell what the likely intent was by how the title was spelled in pre-revolutionary publications. In almost all cases, it was spelled мир. There is just one instance when it was spelled мiр, and it seems likely that it was a misprint.

[ethelward]

> but during the Soviet Union, authorities decided that some letters had to be purged because they were naughty

Just for reference, the grammatical reform had been designed during the tsarist times, started by the ephemeral Provisional Government, and only finished by the Soviets.

[potatoyogurt]

Thanks for clarifying! I was 90% just joking, but I wasn't actually aware that it had such a long history.

[ethelward]

You're welcome! I found it interesting enough that this reform survives three widely different governments to mention it.