The so-called 'Subrahmanyam Formula' was widely used, especially in the mid-1960s and throughout the 1970s, to support India's entry into the nuclear club, despite the country's non-violent Gandhian origins and foreign policy roots in Nehruvian pacifism. The formula did not see any contradiction between striving for socio-economic progress and considering large-scale military development for a developing nation like India. Indeed, strategic deterrence, in which a small but effective indigenous nuclear arsenal would play a key part, was seen as vital to balancing things out in an unequal world carved up by Cold War geopolitics. This ingenious and apparently paradoxical stand has been adversely commented upon, being dubbed 'moral exceptionalism' on non-proliferation by several commentators. Significantly, Subrahmanyam also argued that Pakistan too should look to develop a limited nuclear programme of its own – to establish its own deterrent against conflict. This was met with great suspicion in Pakistani circles, and seen variously as an insult or a challenge. He also concluded in the 90's that India needed only 150-odd warheads to achieve minimum deterrence. And that this had been achieved by 1990, a point noted by many as a good reference to India's nuclear stockpile.