Into the 20th century, Classical Chinese was used to greater or lesser degrees in China, Japan, Korea, and Vietnam as a formal literary standard. However, the use of kana (Japan), hangul (Korea), and Latin letters (Vietnam), which all allowed for the reproduction of each respective language in a more faithful and recognizable way for native speakers eventually overtook the use of Classical Chinese in all of these languages. Even China itself modernized its literary standard in the early 20th century to better reflect the way that modern Mandarin is spoken. But what if a system like that were used to this day, such that the written standard of these countries would be some kind of (potentially partially native-language-influenced) Classical Chinese, with a reading system like
kanbun?
To illustrate how something like this would work, I'll take a sentence written in a kind of hypothetical form of Classical Chinese more or less compatible with Chinese, Japanese, and Korean, and show how it could be parsed all three ways and turned into something usable as a written standard. Apologies in advance to any native speakers of these languages, as I'm sort of taking a hatchet to the grammar of all of them in the interest of trying to create a system that would end up intelligible in this world where everyone's using Classical Chinese. As I know so little about Vietnamese, I won't even hazard an attempt at it, but I imagine it could work in a similar way.
Sample sentence:
今日之晩飯吾已食也。
I've already eaten tonight's dinner.
Chinese:
Nobody would actually speak like this today, in the same way that trying to "read" Latin as if it were Italian would end up sounding somewhat weird. If asked to read this out loud, though, this is what you'd get:
今日之晩飯吾已食也。
Jīnrì zhī wǎnfán wú yǐ shí yě.
But it gets a little more challenging when you approach Japanese and Korean, which have particles and other grammatical function words that have no equivalent in Classical Chinese.
Japanese:
Here's where the readings start to require a little bit of reading between the lines. Or in this case, reading between the characters. If you take the original sentence and fill in with the grammatical particles and verb conjugations, though, you can get something that, while also unbelievably stilted for someone used to speaking Japanese today, is nevertheless recognizable, so that someone reading the Chinese characters would be able to understand, from context, that the sentence should be read as if the missing hiragana are present:
今日之晩飯は吾已に食べました也。
Kyou no banmeshi wa ware sude ni tabemashita nari.
Korean:
Same as Japanese, we've got the issue of inserting the grammatical particles and the verb conjugation. The end result looks similar to the Japanese example, and hangul would (as kana would in Japanese) be relegated to the role of annotative "ruby characters" or as omittable readings for verb conjugation and grammar function words.
今日之晩飯은吾已食사하였다也。
Geumir-ui manban-eun na imi siksahayeotda ya.
While butterflying the very existence of Japanese kana would require going back over a thousand years, and hangul similarly six hundred years, the role of these systems was not always so dominant in Japanese (where hiragana, developed from the cursive script form of Chinese characters, was considered a womanly script) or Korean (where hangul didn't come into common use until the 19th and 20th centuries). Because of the relatively recent development of the modern Japanese and Korean written standards, I'm wondering what it would take to keep China, Japan, and Korea (and Vietnam, too, though once again, I know relatively little about this) all seeing "漢文" and saying "hànwén", "kanbun", "hanmun", and "hánvăn".
Though it seems like a tall order, there's already something of an analogue today, if not on as large a scale as what I'm suggesting here. While there exist Cantonese readings of sentences written in Modern Standard Chinese, the way that people actually speak on a day-to-day basis isn't just with the same words as in Mandarin simply pronounced differently. So there's frequently a difference in the way that a Cantonese speaker might talk on the phone to a Cantonese-speaking friend, and the language they'd use sending an e-mail to a Mandarin-speaking friend. Even we do this to a lesser degree in English, with slang words and contractions that don't get seen often in the written standard. But what kind of geopolitical situation would be necessary to keep Classical Chinese a written standard across East Asia?
For the sake of the challenge, let's lay down a few ground rules:
1. The Chinese languages, Japanese, and Korean must all exist. No getting around it by having everyone speak Chinese.
2. The written standards don't strictly have to be easily legible by readers from other countries—it doesn't have to be a "unifying" standard, so there can be a fair amount of variation in the choice or frequency of characters used between the different standards, but there should be enough overlap that everyday readers should all be able to at least get the rough gist of what a text is saying. People with a greater degree of education and knowledge of more obscure characters, of course, would have an easier time reading these, and would be able to pick up anything in CJK and understand it, for the most part.
3. The base version of the challenge just involves Chinese, Japanese, and Korean, as the Vietnamese system of writing in Chinese characters, chu nom, uses a great deal more locally invented characters and as such would still be quite difficult for speakers of CJK, and furthermore more frequently used Vietnamese grammar. But if you can figure out a way to cause the Vietnamese writing system to drift back into the sphere of CJK, then go for it!