Ramanna speculated that the Shastri endorsement of peaceful nuclear explosive research "must have come from Bhabha". In an interview with the scholar George Perkovich in 1997, Homi Sethna, a former AEC chairman, agreed that Bhabha had prompted this statement, though he added that "Bhabha was able to obtain approval to do theoretical studies only". Historians have interpreted the shift in Shastri's no-bomb position as a concession to the pro-bomb officials within the Congress party and an attempt to win Bhabha's support, which could shield Shastri against further attacks on nuclear policy in the Parliament. The new nuclear policy of doing theoretical research on peaceful nuclear explosives also avoided the large economic costs and international recriminations that would follow a full-fledged nuclear weapons programme.