War between the US and its allies against Russia and China and their allies that aren't US allies unfortunately likely will occur. If we can become allies we now have an extra ally in Asia to help stop them. Initially they will stay neutral then BAM! India and the US invade overwhelming China. India doesn't really like China so it shouldn't be too difficult. Along with that being allies with arguably the 4th strongest nation will help America in case of war. Can't go wrong with that.
If the U.S. became a close ally of India, wouldn't China notice this, and find this threatened. In such a topic, we must take into account that Chin would notice such a thing, and probably move further from the U.S. and towards other allies, weakening relations between the two countries. Closely allying to India would definetly be seen as a threat to China, and create a world divide, as it is almost like the U.S. are preparing themselves for a war against China, not that we want one. The U.S. has been in Asian land wars before, and didn't come out the better in either Korea or Vietnam.