Al Qaeda 'cannot be defeated while Bin Laden is free'

The senior US commander in Afghanistan warned today that al Qaeda would not be defeated unless Osama bin Laden was captured or killed.

General Stanley McChrystal told a congressional hearing in Washington that the terror movement's leader had become an "iconic figure".

He said that Barack Obama's deployment of 30,000 extra troops to Afghanistan meant success was possible. But he said that the mission was "undeniably difficult" and the next 18 months would be crucial.

"I don't think that we can finally defeat al Qaeda until he's captured or killed," said General McChrystal.

He added that his "survival emboldens al Qaeda as a franchising organisation across the world". Bin Laden is believed to be living in the border region between Pakistan and Afghanistan.

The US ambassador to Afghanistan, Karl Eikenberry, who questioned the troop build-up during White House deliberations last month, endorsed the new surge as "the best path to stabilise Afghanistan".

Mr Eikenberry also agreed that Bin Laden was vital. He said it was "important to the American people, indeed, the people of the world, that one day Osama bin Laden is brought to justice".