There is no doubt that India is a valuable weapon for the USA. India is the only country stupid enough to stand on the front line in a war against China.
All the other US allies are smart enough to polite when USA asks them to stand on the front line. "No, you first, boss. I'm right behind ya."
This definitely complicates China's strategic planning because India can easily open a second front if there is a military clash in Korean peninsula, East China Sea, Taiwan or South China Sea.
That's why China needs to counter-contain India. All countries surrounding India should join a military bloc lead by China. Just as importantly, China has to support internal rebels like Kashmir and Naxalites.
The best move here is to give suitcase-sized nuclear weapons to Kashmiri and Naxalites.