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!!!
US lost in Vietnam due to combination of several factors:
1. Geography of Vietnam is not suitable for mechanized thrusts into enemy positions within the mainland. This restricts a state's ability to project overwhelming firepower from the ground in several parts of Vietnam. On top of this, American commanders were terribly restricted in making decisions on their own.
2. American people were not enthusiastic about Vietnam War. When a state's population is against something, it cannot achieve wonders in the battlefield with even the greatest army in the world.
3. Stuff like smart bombs, cruise missiles, computerized systems, stealth aircraft, heavily armored (and advanced) ground vehicles and network-centric coordination among the units, did not exist back then. Therefore, operations weren't highly effective.
4. Vietcong, by itself, stood no chance against American forces in the battlefield. The battle of
La Drang made this abundantly clear to them. Therefore, Vietcong changed its strategy to utilizing Vietnamese terrain to its advantage to draw American troops into areas where they could be ambushed.
5. USSR and China got involved and funded Vietcong operations. They provided sophisticated weapons to Vietcong forces to enable them to shoot down American aircraft and helicopters and challenge them better on land.
6. Racial tensions in the US had a trickle down effect on cohesion and discipline of American forces stationed in Vietnam.
Situation is absolutely different now. American War Machine is incredibly resourceful (with greater autonomy) and American public is no longer split on racial grounds. And Pakistan's geography is not like that of Vietnam.