Infact, USA lost war against Vietnam despite killing in millions, it lost terribly. Even without ICBMs Pakistan can do extreme damage to if there is a war especially nukes....You might have heard djinn ki jaan totay (parrot) main hai. GSLV is infact an ICBM and Pakistan needs satellite launching capability peaceful purposes. No nation can object on the development of a satellite launch vehicle sir!!!
That is a terrible example to give. The vietnam war was the US attempt to provide conventional assistance in a civil war with massive bureaucratic holds on objectives and a military that was ill prepared to fight an insurgency. Moreover, the Vietnam war was a conflict between two powers fighting two different strategies. Had the US used its conventional capabilities with no holds barred in the early days of the war; it would have rolled all the way to Hanoi.
There is nothing Pakistan can do with Nukes that would threaten the US except its immediate interests; which also means the end of Pakistan. Please try to understand that despite your bravado; not too many people would like to die in a ball of flame and have their children burnt from radiation and dying a horrible death. Those are emotions of young men without an understanding of loss.
For Pakistan to be attacked by the US, one or more of the following have to be true
1. The nuclear security is compromised, either by radicals in the military or by a takeover by extremists in the country.
2. Pakistan openly supports an all out assault on the US military in Afghanistan.
3. A massive terror attack takes place which has its origins in Pakistan, and Pakistan refuses to compromise.
There are very little chances of other scenarios in which both the US and Pakistan would be forced into conflict. There may be cold periods of relationships but as such besides diplomatic standoffs there will be no conflict.
As for the GSLV, there is no issue in having one besides that we get our launches done via China and so far have little or nothing to show for sensory satellite programs or otherwise.