"India could have attacked Pakistan many times but due to Pakistan being an atomic power, India could not gather the courage to do so," said Sharif, who heads the main opposition PML-N party.
Pakistan emerged as a nuclear power after conducting a series of nuclear tests in 1998, when Sharif was the premier.
Addressing a gathering yesterday to mark the anniversary of Pakistan`s nuclear tests, Sharif said that conducting the atomic explosions during his tenure made the defence of Pakistan impregnable.
Sharif recalled that when India conducted its nuclear test in May 1998, he was on an official visit to Kazakhstan. He said he had then immediately decided that Pakistan would conduct a nuclear test.
It took 17 days for Pakistan to successfully carry out its nuclear tests on May 28, 1998, he said.
Sharif said he had rejected a economic aid package of Rs 15 billion and decided to go ahead with the nuclear tests.
Pakistan, by becoming a nuclear power, broke the "beggar`s bowl", he claimed. "It was not easy to test the nuclear bomb and I waited for 17 days," Sharif said, adding Pakistan`s security was strengthened by the explosions.
"I was told that I would be blown away if I gave a befitting reply to the Indian atomic explosions. I conducted the explosions, the nation did not make me explode but (former military ruler Pervez) Musharraf blew up my government," he said.
Sharif said President Asif Ali Zardari had a discussion with him to give indemnity to Musharraf when he decided to step down in 2008. He said Zardari had shown no interest in "becoming the president back then" and took over the presidency through deception. "I was shocked when he became the President and so were the people of Pakistan," he said.
He further said the PML-N did not vote for Zardari as the president. The gathering was organised by the Nazria-e-Pakistan Trust, which is headed by Majid Nizami, the editor-in-chief of The Nation newspaper.
Nizami said the nuclear tests silenced threats that Pakistan`s "arch enemy" India had begun to hurl immediately after its nuclear tests in 1998.