The 1995 Nobel Peace Prize winner Joseph Rotblat was speaking on "Security in the Nuclear Age" at Anushakti Bhavan on Thursday in Mumbai. Rotblat said his worst fears came true when the bomb was actually used, not because it was needed for World War II to end, but because the United States of America wanted to display its might to the erstwhile USSR. Rotblat quotedGeneral Leslie Groves, who took over the Manhattan project during its last stages, as saying as early as in March 1944 that the bomb was directed against the Russians and not against the Germans.

"It was a terrible shock to me," Rotblat said, "but nobody believed me." The Germans were already on the point of unconditional surrender and there was no need to use the bomb. Ten years later, Groves himself vindicated Rotblat's stand, when in 1954, he openly said: "There was never any doubt from about two weeks from the time I took over the charge of the (Manhattan) project .... that Russia was our enemy."

The small select audience burst into applause when it was announced that Prof Joseph Rotblat was delivering his lecture on his 91st birthday, born in 1908, the very year, as Dr Jayaraman of the BARC noted, when Dr Homi Bhabha, architect of India's nuclear vision and programme, was born. Indeed, at 91 Rotblat was sprightly. He walked straight and without any aid. His steps were firm of footing. His deliveryclear and suffused with logic - logic laced with excessive idealism, as Professor B M Udgaonkar, chief of the National Centre for Science Communicators that organised the function, noted in his concluding remarks.

The event was not without its inherent ironies. For one, the strong advocacy against nuclear weapons by one of the three makers of the original atom bomb was being delivered at the Anushakti Bhavan, housing too one of the architects of the Indian thermonuclear device (the hydrogen bomb for laymen) Dr R Chidambaram. It was just coincidence that Dr Chidambaram found urgent work elsewhere - in Delhi to be precise. Nor was the driving force of nuclear power NPCIL chief YSR Prasad present ... he had a curious "nuclear" assignment in Turkey!

And it was well that the Indian nuclear luminaries on whom building the nation's nuclear arsenal now rests, were not present. For Rotblat made it plain that scientific positivism was the central cause of the nuclear threat. The arms race was in fact beingconceived and run by the scientists.

Instead of abjuring, the scientists were still working on nuclear weaponsand systems that were not needed. If even one nation has nuclear weapons, it is a motivation for other nations either to develop or procure them, was Rotblat's thesis and to that extent scientists must claim responsibility for the dangers they have created.