A US think-tank has warned that the specter of nuclear war haunts tensions between India and Pakistan and the disputed territory of Kashmir could provide the spark that lights South Asia's nuclear fuse.

The report by Stratfor, a geopolitical intelligence platform based in Austin, Texas, also disputes the classification of Kashmir issue as India's internal affair or a bilateral issue between India and Pakistan.

According to the report, the possibility of the conflict going nuclear has increased after Indian Defense Minister Rajnath Singh's statement of abandoning India's "no first use" doctrine.

The report says decades ago, the people of Kashmir were promised a plebiscite that never took place.

It points out that last February, Pakistan downed an Indian fighter jet but returned its pilot. However, Indian Prime Minister Narendra Modi did not acknowledge Islamabad's conciliatory gesture nor his government has been willing to discuss the Kashmir issue, whose people were promised a plebiscite on their future.