There are many, many explanations for i.e. why didn't China attack Taiwan (yet) and while the U.S. finger in the region helps in some ways, supporting Taiwan proclaiming independence for example may actually not be helping to prevent war there. It seems to me like China is much more reluctant than Russia is to go to such a war, probably because apart from facing domestic nationalistic pressure to do so, there's little actual reason and China does not really want to have its (in Chinese memory) recent expansion of the middle class stopped by facing isolation. Even the Chinese government responds to popular pressure by simply adjusting its policy more often than deploying tanks.
With regards to Russia, Putin, (being a Russian neocon), is using the example of how Russians are sometimes treated in former Soviet countries with regards to citizenship, speaking Russian etc., as well as Ukraine say banning Russian language books or the Russian flag being banned at sports events, which actually helps his cause domestically. If we were actually interested in weakening his grip, we'd strongly oppose such policies imo.