What was Kargil War and why it was fought?

India today is celebrating Kargil Vijay Diwas, the day Indian Armed Forces declared victory over Pakistani troops and militants in the Kargil war. On 26 July, 1999, India successfully took command of the high outposts which had been lost to Pakistani intruders. The 60 day long war incurred loss of lives on both sides and resulted in India gaining the reign over the Kargil sector. But why was this war fought in the first place?

The Kargil War was an armed conflict between India and Pakistan that took place between May and July 1999 in the Kargil district of Kashmir and elsewhere along the Line of Control (LOC). In India, the conflict is also referred to as Operation Vijay which was the name of the Indian operation to clear the Kargil sector.

The cause of the war was the infiltration of Pakistani soldiers and Kashmiri militants into positions on the Indian side of the LOC, which serves as the de facto border between the two states. During 1998-1999, Pakistan sent several soldiers in militant disguise. The aim of these specially trained troops was to capture key posts and severe the link between India and Ladakh, which will force India to withdraw from Siachen glacier and eventually negotiate Kashmir dispute. 

During the initial stages of the war, Pakistan blamed the fighting entirely on independent Kashmiri insurgents, but documents left behind by casualties and later statements by Pakistan's Prime Minister and Chief of Army Staff showed involvement of Pakistani paramilitary forces, led by General Ashraf Rashid. 

The Indian Army, later on supported by the Indian Air Force, recaptured a majority of the positions on the Indian side of the LOC infiltrated by the Pakistani troops and militants. With international diplomatic opposition, the Pakistani forces withdrew from the remaining Indian positions along the LOC.

The war was rare and unique for many reasons: 

-The battleground Kargil-Dras is one of the most difficult mountainous terrains where a war has been fought. The high-altitude of Kargil and Siachen posed significant logistical problems for the combating sides. 

-It is one of the very few instances of direct, conventional warfare between nuclear states (i.e., those possessing nuclear weapons). India became nuclear power after first successful test in 1974 and Pakistan conducted its first known nuclear test in 1998. 

-It is also one of the few instances of direct, conventional warfare between two democracies, as Pakistan had a democratically elected government at the time.