Strategic stability in South Asia is pre-requisite for regional peace and security. The strategic stability in South Asia would require the working of nuclear deterrence between India and Pakistan, safety, security and survivability of nuclear weapons in all conditions of both states and the absence of arms race between them. Both states also need to refrain from developing or introducing any weapon system that has the potential to decisively alter the nuclear balance in one’s favour. For this purpose both India and Pakistan need to contribute by taking responsibility and avoid taking any step that can be dangerous for prevailing strategic stability in South Asia. But, Indian interest in developing the Ballistic Missile Defence capability is a new emerging threat to the strategic stability in South Asia which has the potential to destabilise the regional peace and security.