India's stated nuclear doctrine is that it's "deterrent" is a no first use and for inflicting unacceptable damage in retaliatory strikes. I have a different take on how India should respond to a Pakistani first strike. India does not have to respond with nuclear weapons to a Pakistani nuke strike. Pakistans doctrine calls for use of nuclear weapons when 1) it looses a major chunk of its territory. 2) it looses a major chunk of its armed forces 3) there is severe economic and political hardship caused by ways of blockade. Consider an all out war between India and Pakistan. Considering the above, it's most likely to use nuclear weapons when Indian armed forces capture cities like Lahore, destroy a major portion of the Pakistani fighting force. In this scenario, pakistan has lost already lost the war and our troops are already in control of a lot of Pakistani territory. We cannot nuke our own forces. In the scenario that Paksitan goes in for a first strike without any provocation or way below its threshold, India should still not retaliate with nuclear weapons. India should come out with political and military goals for the next war which is likely to happen in the future. Political goals. India has to dismember Pakistan. We know of Sindh, Baloch, Pakhtun and Balwaristan movements. If Pakistan has already gone nuclear and say destroyed Delhi and mumbai, it gives Indian forces free license to use disproportionate fire power to subdue, kill any opposition that comes in its way and together with local sympathetic forces, help them break away from the current republic of Pakistan as it stands. It should install regimes inimical to it and act as guarantor of future security. This means cities like Karachi, Hyderabad, Quetta cannot be nuked as it has people ready to break away from Pakistan and Indian forces will eventually be there. Again any opposition can be brutally suppressed as we have already suffered population losses due to Paki strike. Military Objective. Complete destruction of Paksitans war fighting capabilities. We capture/destroy their air assets and naval assets. With the break up of Sindh and Balocbistan, these assets can be provided to the new states under Indian protection. There is the china factor in all this India clearly has to use the nuclear first strike threat against china for any interference and since we have already suffered a nuclear strike, it will not be prudent for china to interfere as it will have more to lose than India. India retaliating in a "glass making" contest in a tit for tat attack will not help long term goals. We can kill those against us with guns and with all the brutality without bothering about human rights as we have already suffered population losses. An Indian response to Paki nuke attack really does not have to be nuclear.