Yes, world wars are the result of alliances dragging other countries into a war. Russia’s alliances broke down 30 years ago and are in a shambles now, and Ukraine has no real allies of their own to speak of. So unless Russia does something supremely stupid like attacking a NATO country, there’s not going to be any “world war”. Even if Russia did that, I don’t think there’s any guarantee that even China would back them up, since China would probably prioritize their own survival and make decisions accordingly.
If there is a NATO-Russia war I fully expect China to immediately act to ‘protect’ Siberia by annexing it. That’s the extent of what I expect from China.
The road to WWII started with Japan invading Manchuria.