China understands very well that Only US will want India and China squabble and sparr and destroy each other ....so that US can enjoy the spoils ....
It is for that reason China won't attack India ....
It is Japan ...that China hates and not India .....
US does not worry anything else unless its interests are at stake
All nations will exploit each other weakness on the International Affair. US do need India to help keep an eyes on the Chinese and occasional poke China to rise a tension a little bit but India need US more than US need India, only US can help India out in case Pakistan and China start a 2 front war as the same time.