China vs Korea - a clear partnership?

One of the big political questions at the moment is, should North Korea actually end up in a full scale war with South Korea, whether China will stand by it's ideological ally, or will it forego this role so as not to ruffle the West's feathers? This is none too likely given the myriad of economic and business connections that it is involved in with numerous Western countries. This is an intriguing question and certainly one that should be carefully considered. It is tempting to say that China would not stand by North Korea, and it has already shown a certain unwillingness, even disdain, for North Korea's self-asserted role as challenger to the US and South Korea. But why is this the case?

For one thing, North Korea and China are only allies in ideological terms. China has much that North Korea might want, such as significant economic success and financial aid, but the reverse is not true - North Korea has nothing to offer China in terms of material wealth and resources, and China knows this well. It is thus exploiting it's ideological link with North Korea to keep a country that is on it's south-eastern border on favourable terms and not have it as yet another target in the country's battle with the whole of the Western world. Although North Korea could not feasibly pose a threat to China's economic and military security, it could cause difficulties for it, and this is something which China would, sensibly, wish to avoid.

The real reason China would not come to North Korea's aid is that it simply has too much business with the West. The whole reason for China's economic success has been it's level of imports and business which tie it to Western countries interests, and to side with North Korea in the event of all-out war would lead to severe sanctions and a limit to it's continued growth, as well as adversely affecting it's relations with other countries. China knows that taking on the world in a war with North Korea would be politically futile, financially inconceivable and utterly pointless. There is no doubt that a China at war with the West would produce a significantly more worrying enemy than North Korea, but the fact remains that even in the event of World War 3 , China cannot hope to stand up to the US. The thought of such a phenomenon is quite terrifying, but the final thought to consider is to what extent China would risk world peace and stability for the sake of a small under-developed country in it's Far East. This is questionable indeed.