Adm Mike Mullen
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Afghanistan withdrawal risky, US joint chiefs head says

America's top military officer has admitted that President Obama's decision to accelerate the withdrawal of troops from Afghanistan is riskier than he originally wanted.

Thirty-thousand troops, a third of the force, are to be brought home by September next year.

A new assessment of how quickly British troops should be withdrawn from Afghanistan will be carried out in the coming weeks.

Mark Mardell reports.

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