please don't overestimate the importance of your economy.
when you say "at the cost of China India trade", please keep in mind that india imports our mobile phones, core network routers, cars, power generators, what you export to China? curry? without those affordable imports from China, your poor people will have to spend more and buy these stuff from US or Europe, can you afford that?
As promised, now a discussion on your economic fallacies.
Okay, the market equilibrium does not end at demand and supply. Both are elastic and also inelastic, so a lot of other factors play in. And when this is about geo-politics then the term Geo-Political economies. Of course this is a broad based term encompassing host of geo-politics related economic initiatives but for today let us limit this discussion to your assertion as above.
Because you understand better with examples from India, heregoes.
There was an economic embargo on the space development program of India. It is not that India could not pay for this technology or the world could not manufacture it, but it was not purely economic reasons, it was politico-economic reasons.
However, that led India to invest its own resources and create initiatives so much so that today the cost of ISRO payload on launches is less than 1/10th of international space agencies.
So where am I trying to get at? Your idea that if China is not supplying the product to another country will hurt the importing country is slightly uneducated. A supplier never threatens to dry out customers, specially in cases where it has no monopoly over supplies or the manufacturing technology.
You also understand U.S examples too so, ever wondered why the impending protectionism from Unites States might hurt your economy and why your government is so worried and vocal about it. It is not that U.S will produce cheaper than your cost of manufacturing, it is just that they will not want to buy your product and instead source it internally thus even though expensive but still creating internal demand and not external demand.
So instead of threatening of stopping supplies, you should be worried about the scenario when your importer believes that the threshold of relative benefits has been crossed in favor of creating internal supply sources.
Though you may be naive in making the assertion in your above post but your government understands the implication of this scenario. Case in point, when the Korean Won has been low, your government has been very keen to extend a credit line to Korea and also to create demand in China for Korean products to make the currency hold and recover. While this if done will help Korea in the short term but if not done, will hurt you in the long term. Why? Because, Won at its current levels, for the first time, will make Korean exports cheaper than yours.
Lastly you may want to hide behind technology, but I have something to say to you there. I do business in China, a lot of it and I know that all your state owned organizations took the route of licensed manufacturing in order to get the technology. Nothing wrong it in. Frist it was Germany from U.K then Japan from Germany then Korea from Japan and now it is China from Korea. But what is to be seen is the development of technology by any country based on this licensed manufacturing opportunity. In fact, in the business that I am in, though it is related to manufacturing machineries, the level of research in Chinese companies has been so low that now when the demand for the old technology of the early 80s is over, these manufacturers are in a fix. It is because, the government did not deliver on most of these manufacturing license agreements with the foreign companies and now the foreign companies are not ready to share the new generation technology with them.
That is why hacking and internet espionage is a state policy of China. But then, it was always about gettng things done indirectly or by stealing....... wasn't it.
See that is why you will not get in to a direct confrontation with India in case of a India-Pakistan conflict and hence the saying that you will fight India to the last Pakistani alive.
When you post your GDP numbers the next time, also post the classification of internal consumption and exports. You will then understand why trade is the biggest influencer in geo-political relationships.