Right, and my second-to-last example corroborates that it’s possible to use the present progressive if the entity in question still exists (whereas the thing they acted upon is completely contained in the past). The only question now is whether it is necessary to use the present progressive in such cases.
I’ll give the full context if someone there asks me, but at this rate I’m afraid of giving overwhelming detail that drives potential response-givers away.
Just posting here to let any of you all who are invested in this thread know that I got a response.
The first response basically says that once an event is understood to be in the past, the writer is not bound by the tense, and instead uses tense to convey certain feelings. When the author writes in the non-past form, they can convey a sense of immediacy over the facts/scene.
The second response clarifies that using the past progressive and the simple past are also correct for the sentence that spurred this thread, but that perhaps the present progressive is used to emphasize that such a thing is still a fact even now. There are times in Japanese, where, unlike in English, the tense does not match up perfectly with the events. Apparently Japanese learners of English often feel that English is too strict with its tenses xD
Alright, I think the responses from native Japanese speakers will stop coming in, and now I’ll weigh in. I don’t want to say that Japanese tense is purely random (because it’s not). There is a standard, which we learn from our grammar studies here on BunPro and elsewhere. I think that it’s the sense of what is standard that allows authors to convey different feelings by purposely changing the tense.
Also, it’s important that such changes in tense can only be done when the “correct” tense is clear. One thing that I want to explore more in the future is in what situations certain tenses are flat-out wrong, even after the correct tense is apparent. Perhaps any originally past-tense event can be made into any common non-past tense. But I’m pretty sure it’s not possible to turn anything that didn’t happen in the past into some past tense form. Now it’s a matter of exploring the line and being aware of when the boundaries are pushed.
@NickavGnaro You are totally on top of this one! 
I’d like to add my everyday example:
もう 食べた？
いいえ、まだ 食べていない。
うん、もう 食べた。
Did you eat yet? (casual)
No, I haven’t eaten yet. (I’m still in the state of ‘not eating’.)
Yes, I already ate.
きのう、晩ごはんを 食べた？
いいえ、食べなかった。
うん、食べた。
Did you eat dinner yesterday? (casual)
No, I didn’t eat.
Yes, I ate.
I would agree with both of these responses, it’s sort of summarized in the ている② point. It sort of feels like an emphasis of the state without having to be literal given the preceding past tense clause of DRVの勝利を決定的にした which makes it pretty obvious for the reader.
@FredKore The everyday example exposes what I think is the standard grammar. You use 食べていない when you emphasize the current state. When you emphasize the current state, it implies that the state could be otherwise. In this case, they are asking if you ate recently, and it’s still possible for you to eat today, so it’s feasible to use ていない.
When the question changes to the timeframe of yesterday, there is nothing you can do today anymore, so you can’t answer いいえ、食べてない when asked if you ate yesterday. The result is complete and unchangeable, so the simple past tense is used.
What was surprising is that when it came to the OP’s question, we could indeed use ていない with a complete and unchangeable state of affairs, but it turns out that this was just for literary effect. In everyday situations like whether one has already eaten, trying to make it literary will make you sound like a fool, so maybe that’s why I can’t imagine a scenario in which you would say いいえ、食べてない to the second question.
@s1212z Right, it’s definitely emphasizing state. I think my statement “This entity is still in the state of not having participated in the war” is still a pretty accurate way of understanding the meaning, but it’s definitely a literary bending of the rules, only possible because the correct tense was made obvious, as you pointed out.
For any beginners following this thread, I want to emphasize that it’s not that tenses are thrown around randomly, but rather that you first master the rules so you can learn how and when to bend them and sound smart for doing so.
Going by feeling it seems like you’d to have say something like きのうの晩ごはん in order to use 食べてない for the second question. It’s unrelated but this makes me wonder if 晩ごはん works the same as the word dinner, since you can say “Have you eaten yesterday’s dinner” which treats it like an object, or “don’t text during dinner” which treats like a time period.
Just anecdotally, I feel I’ve come to understand ～ていない much more readily as “hasn’t/haven’t” than as “am/is/are not,” like I originally (naively) thought of it. Even if it’s not explicitly included in the phrase, it almost always feels like there’s an implied “まだ” in front: (まだ) … ～ていない。
That said, I’d parse the phrase in question, 日本人は直接には１名も参加していない, as: “Not a single Japanese individual has been directly involved.”
Edit:
Coming from English, しなかった may still seem somewhat “preferable” to していない here, since the battle is already concluded… but hopefully this perspective can make していない seem like a valid/possible option, instead of causing the “wait… what?” reaction that probably led to this thread 
Thank you, NickavGnaro for going above and beyond to answer my question. I really appreciate it.
Strange reply to a pretty much already solved question. But just as an added insight, since I started teaching English to Japanese people, one thing I consistently notice is that they misuse the word ‘situation’ allll the time. I have come to the personal conclusion that Japanese language speakers tend to view most things as situations, rather than just a random endless course of events.
In light of that, I have come to start to view the て form as a situation marker. 食べていない To not be in the situation of eating. 参加していない To not be in the situation of participation.
The answers here are already great, but that’s just my personal take on it.
Actually I think we have similar thoughts on this. I didn’t bring it up before, but now that you did…
I was reading an article on the necessary vocabulary coverage to be able to understand texts and infer new words from context. Turns out Japanese has an overwhelmingly larger number of words than most/maybe all other languages, and the author was trying to explain the causes behind this.
One of the points the author brought up was that what counts as a word in Japanese is not a straightforward matter, and this could lead to an overestimation. They then showed the following sentence and asked how many words are in there:
食べていらっしゃったらしいから
To me, the answer was obviously 4:
食べて / いらっしゃった / らしい / から
However, a native Japanese commenter said that the example was bad because the answer was obviously 5:
食べ・て・いらっしゃった・らしい・から
The author responded saying the commenter was right, but that foreigners may parse it differently because of how we’re taught it. The fact that there was mutual agreement, and that a Japanese person would call something a simple matter, displaying such great confidence, makes me pretty sure this is not just some dumbass on the internet giving a totally weird idea. It gives me every reason to believe this is how a native Japanese person typically parses the sentence.
Now what this means is that a native Japanese understanding of that sentence separates the て as a whole other, distinct word, while keeping 食べ in its stem!
This got me thinking about the particle で, which is often used to convey the means by which something is done. For instance, バスで行った “went by (means of) bus.” Even when で is use to express reason, as in 病気で倒れた “fell due to illness,” I would insist on understanding it instead as the illness being the means by which the person fell.
With that understanding out of the way, I think the て conjugation in the article’s example sentence is just the same as the で particle. Hence, the sentence should be interpreted something like this:
Because apparently was (gloriously) being by means of eating.
In more natural English, “Because apparently they were eating.” The major difference is 食べ て modifies いらっしゃる, the verb of being, whereas in English, the verb of being modifies the eating.
If we make a simpler version of the sentence:
食べている
I would say to interpret it as 食べ, “eating,” て, “by means of / in the manner of,” and いる, “am/is.” All in all, if speaking about oneself, it would be something like “In the manner of eating is how I am.”
Taking this idea further, I noticed that てくれる and all the giving/receiving grammars that use て really do use this “by means of / in the manner of” understanding of て as its own separate word. For instance, in a song about an ex-girlfriend explaining her reasons to her ex for leaving him for another man, one of the lines is this:
ちゃんと「好きだ」という 言葉でくれるの
Obviously で is a separate word here. But if we had instead done this:
ちゃんと「好きだ」という 言葉を何度も言ってくれるの
we could still separate て out as the manner by which someone says.
So going back to your comment, I think I interpret 参加していない as
参加• し (or 参加し) , then て, so that we have “by manner/means of participating” and then いない, “am not.”
Hope that’s interesting food for thought. Here’s the article I referenced throughout this post: https://linnameigetz.com/japanese-vocabulary#i-5
Saying what constitutes word is difficult in every language. Is “good-looking” one word or two? Hard to say. But it has 3 morphemes: good, look, ing.
Even such a simple “word” as いない can be understood as 2 words because there are two morphemes: いる, ない.
It is good to understand what each morpheme means.
Very interesting stuff on te form. It makes a lot of sense.
Completely agree. Actually, straight from the Japanese dictionary, て、is just 手。But in a grammatical context ‘hands’ are similar to ‘situations’. You can find pretty much all of the meanings for て as ‘and’ listed under 手 in the dictionary. My guess is that the kanji was just removed from the word hundreds of years ago.
I am living for these deep dives! Really helps you look at Japanese from a different perspective. So cool guys
Agreed that the challenge exists for all languages, though I will say I strongly disagree with the assessment that this difficulty in parsing is a significant cause for the substantial difference in vocabulary acquisition that Japanese requires.
Because first I believe the researchers do their best to keep the counts between languages as analagous as possible
Second, even with languages like Korean that have similar grammar, there is a massive difference.
And finally, because the number of additional words you could gain from separating out stems and conjugations is finite: once you have て、い、る、ない counted up as different words in the most spread out way possible, no plain form of the simple present or present progressive will add a new word to any verb stem. So maybe this could inflate the figure by a couple hundred at most, but it’s not enough to explain why in Korean, 5000 words gets you just shy of 90% vocabulary coverage whereas in Japanese, 10000 words gets you just over 90% vocabulary coverage.
So yeah, even though I cringed when the author brought this reason up, I learned something new out of it xD
I think the word count is inflated because of the way Japanese use kanji. They create a lot of words that normally would be two words or more. Sometimes full sentence is required to translate one word.
Examples:
尊敬語 - honorific language
酒屋 - shop selling alcohol
垣根越し - over the fence
If you heard about esperanto it works in similar fashion. There is about 2k commonly use roots in esperanto, but you can combine them to create tens of millions new words. Very elegant system.
If you are interested in morphology checking out esperanto is worth while.
That’s actually a good point, and it’s why I didn’t give up after learning about the massive disparity. This shows there is potential for abusing the count in the following manner:
語 can be appended to many other words:
日本、日本語
和製、和製語
Etc…
Essentially, the Kanji can create a new word out of many already-counted words. So if that’s how the counting was done, then it is possible that you could get this massive scaling effect from a smaller base of root words. But I think then the cause is Kanji rather than conjugations.
Even still, even if it’s the case that the researchers properly prevented such artificial increases in the word count by grouping together word families (which is a common practice), I have other reasons not to feel helpless and lost.
The first good news is that while most languages, such as English, require 98% vocabulary coverage for deep understanding and the ability to infer from context, Japanese requires 93-96%, with the most likely being 94-95%. It’s smaller precisely because of the Kanji can make new words transparent.
Even still, there was a big difference in reaching 95% in Japanese with 98% in other languages, but when I did some of my own analysis, I figured out that once you get past the 5000 most frequent words (as is my case), the vocabulary coverage of Japanese starts to scale at a reasonable pace similar to other languages. That’s what made me not immediately drop Japanese for Korean.
I personally believe that Kanji it the key to success. I don’t understand how anybody can learn Japanese without learning Kanji first. Without Kanji かきねごし is just mumbo jumbo you have to somehow memorise. With Kanji it is quite easy word. Not even necessary to check out in dictionary if you know the Kanji.
I actually got half way through typing this when I gave up and decided to just continue studying because I like these types of conversations too much and end up wasting hours in them haha.
I was going to say that ‘feasibly’, a native speaker could slap any combination of kanji together and create a perfectly logical new word thanks to kanji. It’s why I have given up learning new words. Not because I don’t think I can, but because I am at a point with kanji where the meaning of new words is blaringly obvious most of the time due to kanji. I would say Japanese would have to be the easiest language to aquire new vocabulary at a high level. Stuff just starts making sense without needing to look new things up.
If I remember correctly, you had been adding over 20 words per day over a long enough period of time that you would be over the minimum to understand from context, which is awesome! I aspire to reach that level too