It's less about time being right and more about declining power. People buy into the MSM narrative that East vs West is some King Kong battle and China and its puppet a Russia will take over the world. The truth is that both are failing countries and their governments know it, they have falling populations and their gdp/capita will never catch up with the west, their nominal gdp will start falling in the next decade and their military strength will start falling too - plainly put both Russia and China are at their peaks and its all downhill from here, they look and Japan and see themselves in a decade - the West doesn't have these problems and are just getting stronger.
So China and Russia realises that if it's going to try to prevent the inevitable collapse they must expand and capture new land hence we now have the wars they have and will start