@srevster
Countries do not have any friends but interests.
Indian interests sometimes converge with American interests, this is why India engages with USA. Sometimes Indian interests converge with Russia, Iran or even China.
World isn't a black and white place. There are no good guys and bad guys. On our eastern land border Chinese incursion is a problem. However on our sea border Americans are doing the same thing.
The argument that India should put all its eggs in American basket and burn all bridges with Russia, Iran, etc. is comical and lacks any knowledge of geopolitics.
Coming to diaspora. They do help spreading some cultural influence but nothing more than that. In politics, Jewish diaspora is the only exception. A Hindu living in USA will quickly change his opinion when mainstream narrative is built against India.
The argument that India needs American money/tech is somewhat flawed. You as a libertarian should know that wealth isn't transferred but rather created. India will become wealthy by hardworking people In India not by overseas brown skinned people.
Arguments such as, America will make India rich or Russia will give India super power weapons, sounds ameture. It reminds me of Pakis who constantly look outward for assistance.
On point of lobbying. I don't think India needs to bootlick some random corrupt senator or congressman. That money can be better utilised here in India. Relationships are built on mutual interests not on bribes.
Finally I want to say that India American relationship should continue and even flourish as long as America doesn't interfere in India's internal matter and respects India's independent foreign policy.