That option is not only counterproductive, costly, and opening up another war-front, it will never be needed, silly boy martian. When China goes to warfare, it will have ample of resources to fund her military buildup, the fuel use for running many civilian infrastructure and materials used for civil development will now be diverted to military needs, since you can expect foreign trade to shut down in times of war and there will be worldwide recession. Civilian and trade and export needs far outnumber military needs.
China do not need to worry about an oil cut off in the middle east because in doing so the Americans will put their own economy into recession. What China needs to do is to drag America into a war of attrition in her own backyard on her own terms, and should focus on the South China Seas. Other asymmetric options can be use to destroy American financial centers if push comes to shove, invading Mongolia is not only stupid, it's unnecessary and unethical. China should instead focus on dragging in the American pacific fleet into direct conflict, by first hitting their bases with ballistic missiles or sinking their trading ships or military assets, causing entire trade in Asia to come to a halt, just as American economy could not survive on a cut off in oil supply in the Middle East, they will fare even worst if there is a complete cut off of trade from Asian countries which they are heavily invested in.
The answer is simply to engage the USA asymmetrically, all the more reason why China should have maximum available deterrent within her own backyard. Remember if America cannot win the pacific war, trying to sanction Chinese trade in the middle east will only force China to become increasingly militarized, sanction cannot work without completing your military objectives, and it will force China's hand to engage asymmetrically in Asia. America is not stupid enough to play that Mutually Assured Destruction option. If they could they would have done so. Besides trying to cut off Chinese oil supply from the middle east would mean hurting their own economy, as China have the ability severely halt all American activities in the pacific rim.
The key here is to drag the Americans into a pacific war and drain them, logistically the USA will never be able to keep up with China with even with her bases spread out in Japan Korea Guam or even the Philippines. It will be a far more costly war for the Americans to maintain than for the Chinese, and the Americans have far lest manpower and ability to resupply, and rebuild. If the USA decides to use the outdated sword of Damocles theory, which in fact will end up hurting themselves and their own economy, China will drag the Americans into a pacific war and should America decides to engage, it will be a war that will ultimately and completely sap American economic and military strength and put an end to their hegemony, this is why Chinese main focus have to remain with the South China Sea and the Pacific and never allow America to get a leg up on them or some sort of invincible technological edge on them in this area, which they are not close to having.
China should first and foremost control her own backyard. but most importantly maintain asymmetric parity, as long as China have about the technological parity with the Americans, it will be impossible for the USA to win a war in the Asian region and within China's backyard. They can bring all 11 aircraft carriers on China's doorstep, and it just make it easier to sink or disable them all at once and with that goes their military projection ability. With the right weapons a swarm of fishing boats equipped with moderately advance cruise missiles can take down an entire AC. With no bases to resupply or their logistical bases disrupted and no manpower to rebuild it don't matter how many ships the American have in the pacific, they will all become liabilities.
