Barack Obama leaves door ajar for extra troops

The official White House line yesterday was that there will be no instant response to General Stanley McChrystal's request for extra troops in Afghanistan. But while President Obama used his appearance on The Late Show last night to say Americans were "weary" of the eight-year conflict, he left the door open to sending reinforcements when he said the mission was to protect the west from al-Qaeda terrorists.

"You've got a group of extremists who are willing to slaughter innocents," Obama told his host, David Letterman. "My job as commander-in-chief is to make sure they are destroyed, that their networks are dismantled and that they can't pose a threat to the US of the sort that we saw here in New York."

However, the President said he would be asking "tough questions" of his advisors before making any decision on extra troops. "I've got to make sure that the policy in place is worthy of their sacrifice. That's something that we're going to work through systematically." If the the same systematic approach had been applied eight years ago when the United States first invaded Afghanistan, "we would have been better off."

The other big issue of the night was race. Asked by Letterman whether the opponents of his healthcare reform plans were motivated by racial hatred, as former President Jimmy Carter claimed earlier this month, Obama replied: "It's important to realise that I was actually black before the election".

He argued that the fact that he was elected in the first place "tells you a lot about where the country's at".

He also said that "one of the things that you sign up for in politics is that folks yell at you", and that there would always be a "certain segment of the population that gets very riled up" by attempts to make significant changes. Presidents Franklin Roosevelt, John F Kennedy and Ronald Reagan - the latter "going in another direction" - had all been targeted by what Obama claimed was a minority against change.

In a lighter vein, Letterman and Obama swapped jokes about the First Daughters who, the president assured Letterman, were able to lead normal social lives. "They actually go over to other children's houses. The parents get frisked."

When Obama said of Malia and Sasha: "They basically just goofed off all summer, which I can't do," Letterman was quick to respond: "Others have" - a reference to George Bush's long summer breaks on his Texas ranch.

Despite the security arrangements at The Late Show studio, described by Letterman as "tighter than Joan Rivers's face", the President was able to accept a gift from a member of the audience - a heart-shaped potato.

"When things get tough going for you," said Letterman, "just remember. You, sir, are the owner of a heart-shaped potato."