India and Pakistan ARE NOT siblings. Only India used to think that way for a long time, even going so far as forgiving Pakistan for so many indiscretions in the 1950s and 60s. But Pakistan decided their only way to a "Pakistani" identity was to encourage in their citizens a separateness in every way from India.
The desire to do the opposite of India is so ingrained in the Pakistani psyche, that they do it on a sub-concious level now without even realizing it ...... just see the state of the two countries - India is rising and shining in the world while Pakistan is doing the opposite.
Lasting friendships happen between equals and lets face the truth, Pakistan is no equal of India. Pakistan gets US dollars from Uncle Sam but uses it to fund terrorism in India and elsewhere. Let them divert all that money to their own development. That itself will get them started on reversing their decline and be worthy of India's friendship.