The problem is, we ought to have our trade with a friendly Afghanistan, than just build walls around us and create another Iran.
Most plausible solution that appears to me is for India to have a completely open free trade with Pakistan. India's economy is strong, and market is mature. Pakistan will suffer more in terms of dependency. Once India has a strong control on Pakistan's trades and traders, everything, including militancy, can be controlled.
But those sitting in Rawalpindi are not fools, they will make sure this day never comes to fruition!