Are the Japanese trying to colonize China again?
If the underlying causes are not fundamentally dismantled then it could certainly happen again. It's only been 80 years since the end of WWII, a lot can change in another 80. The northern nomads didn't invade China every century, but some semblance of permanence of peace has only been achieve with the assimilation of the cultures during the Qing dynasty. Now it's been relative peace for some 200 years, with no end in sight.
Now with that said, two important points need to be made. First is that Japan does not historically have a habit of invading China repeatedly, neither does China have of Japan. As such, I don't believe assimilation is necessary to achieve peace between the two. It's more like China and Korea, coexistence is possible.
Second, I disagree with the other posters here that the Japanese imperial institution needs to be removed. Sure, the emperor played a role in the invasion of China, but I don't believe it's the key underlying cause. I believe that the Japanese belief of superiority, to the point that atrocities committed against China and the rest of Asia is inconsequential such as the atrocities I committed against the ants in my backyard, is a fundamental underlying cause that has not been completely dismantled. It's OK to feel superior, many countries' nationals feel that way, but how it's channeled is very important. People feel superior to bugs, and for that reason some people ignore them, while some people crush them for fun. It's the latter way to channel that feeling of superiority that needs to be avoided.
