Former Soviet leader Mikhail Gorbachev said it was “impossible” for coalition forces to secure victory in Afghanistan in a BBC interview broadcast yesterday.

Mr Gorbachev, who was in charge when Soviet troops withdrew from Afghanistan in 1989 after a war lasting nearly a decade, added that the alternative to pulling out troops was “another Vietnam” which “wouldn’t work.”

He backed US President Barack Obama’s July 2011 date for starting to withdraw troops and handing more responsibility to Afghan forces, even though he said it would be “difficult.”

“Victory is impossible in Afghanistan. Obama is right to pull the troops out no matter how difficult it will be,” Mr Gorbachev told the BBC.

He added that it would be “difficult” for the US to pull out of Afghanistan because the US had previously trained militants there who were still “terrorising” the region.

“It will be more difficult for America to get out of this situation. But what’s the alternative? Another Vietnam? Sending in half a million troops? That wouldn’t work,” Mr Gorbachev added.

The US and NATO have more than 150,000 soldiers in Afghanistan fighting an insurgency led by the Taliban which, while concentrated in the south, has spread to previously peaceful areas of the north and west.

The Taliban were ousted from power by a US-led invasion in 2001.