Just 3 questions:
1. How you can keep this disintegration going through peacefully without a civil war?
2. How you can prevent this civil war from spreading into India?
3. How you handle the massive refugee group coming to your country?
1. Civil war in Pakistan is already going on, you may chose to not see it but its right there, happening now. When a state's air force starts bombing its own citizens everyday, when it becomes the state with highest capital punishment in a year, it means things have gone out of hand. So no worries on civil war front, it is going on there and it will have serious consequences for them.
2. Pakistani civil war WILL NOT spread to India because of several cultural , religious and territorial issues. However, there is a strong chance that it will stimulate the ongoing insurgency in Xinjiang and Tibet. All Uyghurs who are getting trained in Pakistani terror camps will have more freedom to hit in China and retreat back to Pakistan. So China is creating a monster who is hitting her back in the same coin. Funny part is, its going to increase now.
3. No refugee from Pakistan will EVER come to India because of sealed border with 24x7 monitoring. They will rather spread to Afghanistan, Iran and China as their borders are porous. Any refugee from Pakistan is more probable of getting shot at the border as an intruder terrorist. Even the sea route is sealed as it was shown recently by ICG.
So my friend, the civil war in Pakistan has already begun. All those who felt that a strong Pakistan is in India's national interest, they will be proven wrong. As Stephen Cohen says, Pakistan as a state has serious identity crisis as it doesn't know why it exists. On top, most of Pakistani property is in the hands of few feudal landlords including the PM Nawaz Sharif's family (has quite an empire of Rehman sugar mills). The rest of property is owned by the Paki military. So the common Paki man has to either live like a surf or a bonded labour on these feudal lands or become a terrorist and kill for livelihood. It cannot go on forever and the day for payback has now come.
Pass the popcorn please !!!