Earlier quoted context omitted.
India isn't an ally of the US as far as I know, it's a leader of the non aligned nations in the UN and accused of sanctions busting for cheap oil from Russia. It's not a member of any of the NATO class treaty bodies, and it actively purchases arms from the FSU, and repudiated the non proliferation treaty.
True, India is an ally of Russia and not USA/West. But in case of war, USA can do three things: 1. Support China: China has similar military to USA and 4x the population. If USA does support them, china will strongarm literally every country in the world and become the hegemon. 2. Stay Neutral: This would mean every bigger country can attack and capture nearby smaller ones. The reason expansion wars don't happen now…
What the US almost always does. But I am sure we will send some troops to sit on the sidelines and make sure it is a fair war.