"We should tell the Pakistani Army leadership that if we learn one of their officers is involved in harbouring terrorists, planning terror operations, or tipping terrorist bomb factories off to drone raids, we will make it personal," said Bruce Riedel, a former CIA official and now a senior fellow in the Saban Center at the Brookings Institute.

"Don't sanction the country or the ISI; sanction individuals. Hold them accountable. That officer will go on our terrorist most-wanted list, and we will seize his property if we can, arrest him if he travels, expel his kids from school here or in England, and – if he is truly dangerous enough – take direct action," he wrote in an article published by Tablet.

"We should not do this alone. We should get allies, especially the British, to help, since Pakistanis love to visit London and send their kids to school in the United Kingdom," said Riedel, who is the author of the book 'Embrace: Pakistan, America and the Future of the Global Jihad.'

He argued that the US will need a base to stage operations into Pakistan for the foreseeable future.

"We can hope al-Qaeda will implode soon, but we cannot count on that. The Arabian Sea is too far away," he noted.

"So, we need a US military presence in Afghanistan so we can continue to send drones and commandos over the Pakistani border. We don't need 100,000 troops in Afghanistan, but we do need Afghan permission to operate in that country for the long term. That is the other hard lesson of Abbottabad," he said.

Riedel said that there are growing evidences that some part of the ISI helped Osama bin Laden in hiding safely for more than five years in Abbottabad.

"Now the evidence is growing that at least some part of the ISI and the Pakistani army was, in fact, actively complicit in hiding Bin Laden for the past five years," he said

Referring to a New York Times news report, Riedel said that bin Laden was in regular contact with the Harakat ul Mujahedin terror group, which the ISI created in the 1980s to fight India.

"The Harakat ul Mujahedin has loyally worked with the ISI for decades, and its members hijacked an Indian airliner in 1999 with al-Qaeda and the ISI. Fazlur Rehman Khalil, head of Harakat ul Mujahedin, lives openly in an Islamabad suburb," he said.

"If Harakat helped Bin Laden, it is not hard to imagine that someone in the ISI knew that the world's most wanted terrorist was been hidden somewhere inside Pakistan," Riedel said, adding that there is other circumstantial evidence of official Pakistani complicity in hiding Bin Laden.

"The commandant of the Kakul academy in 2006 was General Nadeem Taj, the right-hand man of former President Pervez Musharraf. After his service in Abbottabad, Taj became director general of the ISI in late 2007," he said.

"On his watch, the ISI blew up the Indian embassy in Kabul and Benazir Bhutto was murdered by al-Qaeda. The UN investigation of Benazir's murder held the ISI as possibly culpable," Riedel said.

Noting that in September 2008, the Bush Administration demanded that Taj be fired, Riedel said, instead, he was promoted to corps commander.

"The terrorist attacks on Mumbai came a month later, and we know the ISI helped plan that. Taj had the means and access in 2006 to help Bin Laden, and he is clearly a problematic partner. Not a smoking gun by any means, but suggestive," Riedel said.

Pakistan, he said, is home to more terrorists than any other country, many of them harbored by the Pakistani army and the ISI.

Bin Laden's deputy and now heir, Ayman al-Zawahiri, is probably somewhere nearby, he said.

"Khalid Sheikh Muhammad, the tactical maestro of the September 11 attacks, was living in Pakistan's military capital, Rawalpindi, when he was captured (albeit with the ISI's help). Mullah Omar, head of the Afghan Taliban, was trained by the ISI and commutes between Quetta and Karachi," he said.

"Hafez Saed, head of Lashkar-e-Toiba and mastermind of the Mumbai massacre, lives and preaches openly in Lahore.