Russia and China are both suffering demographic collapse so it will be very difficult for them to hold on to what they got let alone expand.
The Chinese are extremely racist and would not want to takeover countries with non-Han people in them like the Philippines, Vietnam, etc. They would just make them a part of their economic sphere, just like the US has included Canada and Mexico into our economic sphere.
If we can prevent a massive nuclear war over the next ten to twenty years, then I think we'll be safe for quite a while as the world becomes divided into three or four economic regions that fight using tariffs and import/export regulations rather than bombs and bullets.