Yes, no great power or superpower (US) will risk WW3 over Crimea. 2050 and out, the answer becomes a maybe. Russia will really be a shell of itself by 2050 and esp. 2100 with a dwindling population. Would the need to retrench present itself due to fiscal/internal political restraints. Possible but understand that Crimea has a lot to do with Russia's ability to project power, esp re its lack of ports.
Which would open the door for China (by which point, it will likely surpass the United States in having the largest economy in the world) to engage in similar behavior, like reclaiming Mongolia and other territories once occupied by the Qing Dynasty empire at its height:
Only a strong Russia under Putin is preventing them from doing so. Once that changes....
I don't think people fully understand how much more of a threat China is. Russia basically just wants to maintain the small sphere of influence it still has (ie defending Assad) and to dominate areas that have been Russian for centuries (as in Crimea). China on the other hand is low-key economically colonizing Africa and has become the top trade partner of almost every country in Asia, rapidly giving themselves influence to rival America. New cold war? Probably not, only because the US and China are top trade partners, but maybe still a bit by proxy.
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