U.S helps india to apply this equation ( india chineese war = destruction for each )
Unfortunately they believe in the concept of the enemy of my enemy is my friend.
Some take that litterally, but in actual fact what it really means is the enemy of my (biggest) enemy is someone I can use to hurt my biggest enemy and I don't really care what happens to either... if they wipe each other out fighting is as good a result as any for me.
Lets look at that track record... they used Communist China in their fight against... Communism... but it was declared as a fight against the Soviet Union. The result is that the last major communist country has now become a threat and Russia still has all those nuclear missiles it had that made it a threat in the first place.
The strategy now will likely be to break up the Russian federation to the point where it is a lot of little states that couldn't be trusted with nuclear weapons, and in Chinas case they will try to use either India or Russia against China and stir up things to try to get a conflict/competition from.
They also trained and equipped the rebels in Afghanistan... the money they spent created forces that became the Taleban. That worked out pretty good too right?
India just needs status quo and keep patience as Pakistan is on self destruct mode already.
Sad to say that the US has abandonned ship and is scrabbling onto the good ship India... if India realised that the first thing they will do when they get on board is head to the captains cabin to tell him he should point his guns at that chinese ship over there and that they can't trust the Chinese captain... but you can trust them...
And also In India's case it is weapon sales and large market for US companies and maybe India on their side against China but we have to wait and see how will this paly out in long run.
In Pakistan's case it is so called war on terror, supply routes for NATO and maintaining Pakistan as a hedge against India and keeping India on edge.
The US has clearly lost interest in Pakistan... Pakistan was a useful ally in the war in Afghanistan, but that is ending in 2014 so that is when their "interest" will end. After that watch American interest shift to India, and in a way that is in Indias interests as that will weaken Pakistan in almost every sphere.
It could be as bad as Iraq after the Kuwaite invasion... before that Saddam was the good guy keeping them Persians in check. After he was an evil dictator that gasses his own people!
After the US pullout in 2014 how will Pakistan be treated? They have no interests there anymore.
I think Pakistans real future rests on the untapped mineral wealth of Afghanistan... we all know the Taleban gets most of its support in Pakistan so the real question is who does Pakistan back?
If the US tries to leave a presence in Afghanistan then probably their best bet would be to support the Taleban to overthrow what will be a US puppet government and then hopefully take afghanistan quickly and when things die down so to speak create Pakistani mining companies and go in there and dig... with Taleban protection... they wont approve of drugs (which will make the Russians happy... in fact Pakistan could contact Russia and get some cooperation deal in getting rid of the poppy fields and benefit from something the Taleban will probably do anyway).
This, being something the US would never do, could be used to protect Pakistan from any UNSC resolutions over the new Afghanistan.
Of course if the US just leaves (which is very unlikely) then you need to look at where negotiations between Karzai and the Taleban go and be the nice supportive neighbour.
One of the problems is the split of nationalities so an agreement to split Afghanistan into two autonomous regions might actually be a good place to start in negotiations.