Re: Siachen ..
Let’s call a spade a spade. The reason India will not abandon the position with out written guarantees is because of the Kargil incursion on 1999. By tradition, Siachen, prior to 1999, was abandoned in winter due to the hostile conditions. This was essentially an understanding between the Indian and Pakistani armies starting from the Shimla Agreement, of 1972. In 1999, Musharraf sent in the Northern Light Infantry to occupy Indian positions and spark a regional conflict.
As for agreements, Vajpayee and Nawaz had reached an agreement in 1999. India would have given up parts of the Valley that spoke Urdu and kept the parts that spoke Kashmiri. The Pakistani position would have been placated, Vaypayee and Nawaz would have walked away with the Nobel Peace Prize and the India and Pakistan conflict would have been over! However, the Pakistani Army didn’t want that…so we had Kargil instead.
Interestingly enough, when Musharraf was in power, India and Pakistan reached the same agreement again! This time, Musharraf was thrown out. The agreement is still alive and has the backing on Zardari.