Since 1998, a major element of India’s nuclear doctrine has been the development of a nuclear triad: the ability to fire nuclear weapons from land, air and sea. Recent years have seen India concentrating on the sea-based element of its nuclear deterrent, in particular through efforts to develop a ballistic missile submarine (SSBN).

All the major nuclear powers have placed their faith in SSBNs, primarily because they are extremely hard to detect and destroy, hence assuring a state’s retaliatory capability. The fear of a second strike, in turn, helps maintain effective deterrence between nuclear adversaries. ...