Lets introduce a little bit of reality into these scenarios....do you really think that India has the capability to encircle the entire Siachen glacier and that too from the Pakistani side??? Are you aware of what the terrain is like? You do not have enough acclimatized troops to maintain anything beyond the existing brigades and here you think that IA would be able to go across the LoC in the mountainous train and take over the Glacier???
Once Pakistan sits on the glacier, just like it sat on positions in Kargil, it would have to be a unilateral withdrawl....no amount of Indian action can get it back. Pakistan first of all would never allow IA to come across to encircle the glacier...you can't shove Tanks and Artillery all over that terrain...the only thing you can bring to bear is air support but that too goes only so far......Gen VP Malik was asked if IA can go into Azad Kashmir and take it over (essentially meaning the same route that IA would need to take to get to the Glacier from the Pakistani side) and he emphatically stated NO! So lets not get too carried away with what the IA can do...Indian re-occupation of Kargil was only made possible because Pakistani forces were told to vacate the heights....its was not Indian Military pressure, rather diplomatic pressure...there is only so much that you can achieve with military force.