The "west" has never really aided with or aligned with India. In the 1971 war with Pakistan[0], when Pakistan was carrying out genocide in Bangladesh, America sent its warships to attack India. They only backed off when Russia sent its own warships. It's been almost 50 years, but India hasnt forgotten than incident, and it still, to this day, affects public opinion/policy.
In most diplomatic disputes, the Ussr (and later to some extent, Russia) sided with India, while USA sided with Pakistan.
Even though India has been a democracy, relationships with the USA (and most western nations) have been cool, at best.
>> wouldn't that come back to bite them potentially if China aggressed on India in a potentially parallel border dispute?
I doubt USA would do anything if China and India went to war; USA and India are sort of aligned in trying to contain China, but in itself this isnt a strong enough factor to counter all the other bad blood over the years.
It also doesnt help that the American political system is a bit of a Jekyll and Hyde-- one President can promise you anything, the next will completely overturn it. Trump tearing up Obama's Iran deal is an example (but this goes beyond just Trump). Most Asian/Arab countries know you can't trust America-- Obama betraying long term ally Mubarak (in Egypt) and throwing him to the wolves is another example.
Hate Russia all you want-- but the general feeling is: Your deals/relationships with Russia won't change every 4 years, and you can build long term plans.
0. https://en.wikipedia.org/wiki/Indo-Pakistani_War_of_1971