A world without America

Despots everywhere would rejoice.
The world economy would be crippled.
Millions would die of hunger, infectious disease, and violence.

Then, in time, things would get really bad.

 

If we were to follow your logic that China's neighbors would be less safe that would be, like Tibet China would eventually conquer them. Which is accurate. Unfortunately every time China takes a country they get a whole new batch of "neighbors" who are now "less" safe. Basically China would not be helping these other countries for the good of man kind. They are fattening up the Turkey dinner in advance of Thanksgiving. Infrastructure lasts a long time and is used for things other then trade, for instance the speedy movement of troops. Imagine if in WW2 Russia had had a modern infrastructure. Moscow would have fallen instead of all those tanks bogging down in the mud and snow of the Ukraine.

 

Smaller countries like Taiwan, Vietnam, Nepal, Bhutan and the Central Asian republics would be in trouble. But bigger countries with nuclear arsenals: India and Russia would not be easy pickings for China.

 

Not easy, but that is just it under American hegemony they do not have to worry about that at all. America can be annoying, heavy handed, and arrogant but we do not conquer our neighbors. It takes extreme situations for us to mobilize against a country and even then we do not take territory permanently. If China takes a country they TAKE it and keep it forever.