I don't think US and India can ever be clubbed together. India will be left alone. From what I have seen of US flip-flop foreign policy since 1935, I don't expect the US to act predictably. To your moot point, yes, it will be a nightmare, but a very bad one at that. IMHO, India needs to pull all stops to destabilize as much of Pakistan as possible, regardless of whether Pakistan has nukes or not. The objective is a physical connection with Afghanistan, thereby, cutting off Pakistan from PRC.
I really believe these days Russia pampering Pakistan in favour and USA recent willingness to supply f16 to Pakistan against India wishes is not related to India centric but they are Syria centric.
USA trying to get access in to Indian Ocean which is for long term foot print. Now the way alliances are being formed USA (nato) ,Saudi vs Russia ,China,Iran ..... Now these players tend to acquire paki bi itch in there favour, hence they side lined our Indian concerns which is short term . They will come come to us for business deals again.
Starting from Georgia ,Ukraine ,Yemen and Syria USA provocations of war are very serious , Iran slightly managed to escape from war path in Yemen (pakis escaped by not joining Saudi). Now different door for war is being knocked in Syria and pakis are being invited with sweets.
These indications tell only one thing, if USA miss waging war in Syria they loose final opportunity to destabilise Asia by dragging China, Russia, paki in to war .
Upon destruction of Asian powers , paki won't sit quiet and use every option to drag India in to war path. What Putin said recently is right we are heading towards 3rd world war. India should be ready, and try its best that no war will happen in Syria.
That should be our priority. If we are successful in that, USA will leave Asia due to its economical problems like ussr.
Mean while India should identify its internal enemies and track them.