The Youtuber Whatifalthist does some analyses and predicts a multipolar system. The USA and China are basically arranged right now in a binary system not dissimilar to the Cold War, but due to Chinese demographic instability and American decline from economic and social factors, the probable truth is that power will start to be split between multiple world powers again. Taking things, a tripolar or multipolar system with the US, China, and Turkey (taking Whatifalthist's predictions as accurate, which, honestly, they don't seem too outlandish) seems realistic by 2100.