It all sounded so simple during the campaign. There was nothing wrong with Afghanistan that couldn’t be sorted out by ditching the idiot Bush for a president who knew what he was doing and who would not be “distracted” by Iraq.

That was then. Now Obama faces a situation that every day becomes eerily more like the one that confronted LBJ 45 years ago.

Your commander in the field tells you that without more troops the war is lost. You doubt whether pouring more men in will bring victory and are frankly desperate to get out. You could probably weather the resulting political firestorm by blaming your predecessor for the mess you inherited.

But you cannot afford to quit because of the effect, both psychological and material, on neighbouring territories.

Obama is stuck. He cannot honourably stay in Afghanistan without giving the general the forces he says he needs. But if he gets out, the effect on Pakistan could be catastrophic.

Barack Obama, hero of the anti-war left, and now a prisoner of the hated Domino Theory that gave us Vietnam.