Hmm. Well, Japan went to war in '41 mainly because their primary sources of oil and steel were being cut off (by FDR). Without it their war machine, already heavily engaged in a war in China, could not continue to function for long. So they engaged in a tremendously risky new war with the USA, Britain, and Holland so that they could sieze oil-rich areas in Indonesia.

If China feels the squeeze too severely, it does create a certain amount of risk of a future conflict. They would look for oil a bit nearer to home than Indonesia. They'd look for it by moving west through the passes of Aghanistan and into the Caspian region and the Middle East.

Theoretically, that is....I'm not making predictions, I'm merely considering various possible ramifications of China running short of oil.

I'm sure there are other numerous other possibilities as well.

If a country decides to go to war to secure oil, it will make sure its military sector is the one that gets the available oil...and the civilian sectors will face rationing.

So I don't think that an overall national shortage of oil would necessarily stop the Chinese military from launching a large military campaign...it would just force them to succeed quickly in securing new sources of oil...as the Japanese did in early '42 when they captured the entire Dutch East Indies...or to face a collapse of their effort not too far down the road if they failed to secure those new sources of oil.

By early '44 the American submarine campaign had strangled Japan's lifeline of merchant shipping by sinking most of their tankers and other merchant ships, and from that point on the Japanese were desperately short of oil and their war was irrevocably lost.

Anyway, there are other things (besides military campaigns) that the Chinese can do if they want to throw their weight around. They hold a lot of American dollars. They provide a vast amount of consumer goods that the West wants. So there are a number of things they could do, I would think, to get the oil they need.