ISLAMABAD: India may not be able to fully defend itself from a possible Pakistani nuclear strike in a conflict despite the country's heavy investments in developing anti-ballistic missile systems , a Russian nuclear expert has cautioned. Petr Topychkanov , a senior researcher at the Carnegie Moscow Centre's Non-Proliferation Programme, said that despite large scale cooperation between India and Israel for the development of a ballistic missile defence system and India's efforts for acquiring S-400 defence systems from Russia, it is "very far" from defending itself from a Pakistani missile attack."Even in 10 years and with the huge budgets that India plans to spend on the development of nuclear weapons and capabilities, it is difficult to imagine it will be able to defend its territory from possible strikes from Pakistan in case of conflict," Topychkanov was quoted as saying by the Dawn.Talking about India's candidature for the Nuclear Suppliers Group (NSG), Topychkanov said the world will be cautious about India."The nuclear waiver given to Indian became a very important part of the lesson for the international community because Delhi did not give a lot in exchange, it didn't change policies and approaches," he said.About Russia's policy for strategic stability in South Asia , Topychkanov said Moscow is interested in regional strategic stability and is working on avoiding crisis in the area.He said despite longstanding strategic partnership with India, Russia was developing relations with both Islamabad and New Delhi India successfully test-fired its indigenously developed supersonic interceptor missile from a test range off Odisha coast on Sunday which is capable of destroying any incoming ballistic missile, prompting Pakistan to say that it would disturb the balance of power in the region and it plans to raise the issue at the international level.