For a war movie, it is not bad, at least have some plots. The sad truth is that there is no winner in this war, that's why it's dragged for three years and no one can claim to be the winner. But since it's a movie, not a documentary, I don't think we need to discuss the truth or fiction here. However, many reviews are anti-China, I highly doubt those people ever watched the actual movie.
Review of The Battle at Lake Changjin
