Mr Panetta's statement comes just over a week after a statement made in Islamabad by US special envoy Richard Holbrooke that the US intelligence community did not know where the al-Qaeda leadership was hiding.

BBC: Bin Laden 'is still in Pakistan'

There is no question, as I've mentioned before, that the cooperation that we have had from Pakistan has contributed to some of the successes that we have had in taking the fight to al Qaeda, in eliminating senior al Qaeda leadership from -- removing senior al Qaeda leadership from the battlefield.

WHITEHOUSE: Press Briefing

Indeed, to the extent that radical Islam grew stronger during this encounter, it was not the Sunni zealots of al-Qaeda who benefited but their rival pretenders to leadership of the Muslim world: notably the Shia leaders of Iran and, after the 33-day war with Israel in 2006, Iran's Hizbullah co-religionists in Lebanon.

ECONOMIST: Gilles Kepel

Scheuer used to be head of the bin Laden unit at the CIA's Counterterrorism Center (which is different from the newer National Counterterrorism Center), and he says he thinks his successor is the person leading the day-to-day hunt for bin Laden and the rest of al Qaeda's leadership.

CNN: Who's in charge of hunt for bin Laden?

And Iraqi forces have taken the fight to al Qaeda, removing much of its leadership in Iraqi-led operations.

WHITEHOUSE: The End of the Combat Mission in Iraq