There is a saying, “History is always written by the winners.” It may not be entirely true but its meaning is likely to be the case as history is in fact written by the winners most of the times. Nevertheless, the saying can be wrong at the same time. The saying can be true or false depending on the definition of the winner. So there is also a saying, “History belongs to those who write it.”
It is wrong to deny something outright just because there are no records although there was such tendency in history in the past. For example, did early humans in the Stone Age only use stone implements? No. They may have used wooden tools as well. They may have lived in a tent made of wood and leather in the open field instead of a cave. No such trace is found, however, since wood and leather are meant to decompose with time. These facts were not acknowledged at one time on the grounds that there was no evidence. This is a misuse evidence-based decision.
I also believe early humans in the Stone Age did use woods and tents and that it is okay to write it in history books. However, it would cross the line to say, “They may have used wooden tools looking like this,” or “They may have gone to war with wooden swords.” Even if you are confident about it, you should not say such thing without evidence. This is why records are important in history, especially so in the history of war. Yesterday, I met a Korean War veteran, who is over 90 years old, and he said he was a machine gunner. The Korean War took place not so long ago in the mid-20th century. His testimony should have been documented in an extensive and detailed manner but the work has not been done properly.
People would say that documentation of the war has been done pretty well, which I believe is not enough. The work should have been started in the 1990s at the latest. It is too late to say this now. In the 1990s, I was not capable of doing so and did not have the ability to ask for help. The reason why I am saying this now is because I want our society to know the value of investing in records.