INDIA could expand its nuclear arsenal to ensure a ''minimum deterrent'' if other nuclear powers increase their stockpile of warheads, an architect of the country's nuclear weapons program says.

Dr A.P.J. Abdul Kalam, a former president and a key player in India's controversial 1998 nuclear test, said his nation needed weapons of mass destruction because ''strength respects strength''.

Dr Kalam ... "strength respects strength". Credit:Peter Rae

''Nuclear weapons spread to our borders, our neighbours were all getting nuclear weapons so we needed them,'' he said in an interview with the Herald. ''On all sides around us, other nations had nuclear weapons so we have them for deterrent, for self defence.''

Dr Kalam said India only wanted a ''minimum deterrent'' and was not in competition with its nuclear-armed neighbours Pakistan and China. However, when asked whether the stockpile of warheads needed for a minimum deterrent should rise if other countries increased their nuclear weapons capacity, Dr Kalam said: ''Yes, the deterrent is always reviewed with reference to the world situation.''