Why must India make territorial concessions to Pakistan?

Former Foreign Secretary, Kanwal Sibal, has a very timely and well-articulated piece in the Daily Mail on India’s position on Siachen, amid rumors that New Delhi was planning some sort of strategic climbdown in the larger interest of bettering India-Pakistan relation.

Why must India make territorial concessions? | Mail Online

These bureaucrats don't even understand wht the issue really is .. U think India gives a hoot abt tht piece of land? We have occupied it cos it symbolically represents something larger ..Its a message to the enemy .. Tht we r not even ready to give away this barren piece of land so how can they even think of kashmir .. There r few things which r way above all logic .. This is one of them .. Siachen is a symbolic gesture made to pakistan .. So one can't even think abt making any concessions to pakistan .. Today they r asking siachen .. tomorrow they will ask kashmir .. then wht?