
China questions sovereignty of ex-Soviet states
China’s ambassador to France says sovereignty of Ukraine and other former Soviet republics isn’t clearly defined in international law
Right now the question applies to the Crimea, but that's nowhere the limits on China's questioning. In the past, questions of this nature would have been decided according to America's power and America's power to convince the rest of the world.
But now that the balance of power is shifting, there appears to be a question of legitimacy being raised by China, that isn't a foregone conclusion.
In any case, Russia will have to be defeated before it can ever lose the Crimea. It's too militarily strategic in importance to Russia to allow otherwise.
The question then becomes, whether the bulk of world opinion see it Russia's way.