Here we should also elaborate the reasons that why the both countries are keeping their armies in Siachen..

The current conflict over Siachen Glacier is part of the bitter, unresolved dispute between Pakistan and India over Kashmir - a dispute which dates back to the independence of the two states in Agust 1947 as a result of the partition of the Indian sub-continent based on Muslim and Hindu majority populations. The Siachen issue arose over the interpretation of the precise direction of the line of control beyond grid point NJ 9842 as it turns through the ice-covered area of northern Kashmir. In the Karachi Agreement (27 July 1949), it was specified that the line would move "north to the glaciers" from Khor, the last identified location.

The Siachen glacier is the highest battleground on earth, where India and Pakistan have fought intermittently since April 13, 1984. Both countries maintain permanent military presence in the region at a height of over 6,000 metres (20,000 ft). More than 2000 people have died in this inhospitable terrain, mostly due to weather extremes and the natural hazards of mountain warfare.

The Indian army controls all of the 70 kilometres (43 mi) long Siachen Glacier and all of its tributary glaciers, as well as the three main passes of the Saltoro Ridge immediately west of the glacier Sia La, Bilafond La, and Gyong Lathus holding onto the tactical advantage of high ground.

The Pakistanis control the glacial valley just five kilometers southwest of Gyong La. The Pakistanis have been unable get up to the crest of the Saltoro Ridge, while the Indians cannot come down and abandon their strategic high posts.

The line between where Indian and Pakistani troops are presently holding onto their respective posts is being increasingly referred to as the Actual Ground Position Line (AGPL).

Now come to the strategical reasons that why India wants to be there and why its obligation for Pakistan to protect Siachen. As Siachen Glacier is an integral part of Baltistan, a region in Pakistan's Northern Areas, Pakistan responded quickly to forestall Indian agression and foil the Indian attempt at using the passes over glacier to invade and occupy more territory. The Indian occupation of Siachen Glacier also threatens the Karakoram Highway (the old "Silk Route"), which is a major road linking Pakistan to China at the Khunjerab Pass. By its strong resolve and determination Pakistan has thus prevented future Indian aggression in the region. For Pakistan Siachen is much important strategically. This strategical significance of Siachen is the also the reason for India to invade.