Both leaders agreed there could be "no artificial timetable" to pull out of Iraq on political grounds. Bush, with an eye to his legacy, said the US and Britain would withdraw on the basis of "success" as the Iraqis take responsibility for their own security. Brown insisted that he could not "trade numbers" between Iraq and Afghanistan. But that, in effect, is what he's doing. As our service chiefs have been complaining, troops can't be in two places at once, and more are urgently needed in Afghanistan.

The body language between the two leaders today was warmer than at their rather frosty first talks at Camp David last summer. Bush looked on like a proud uncle when Brown spoke, even putting a friendly hand on the PM's arm. Brown didn't reciprocate, fidgeting with his cufflinks when the President embarked on his usual rambling answers. But he praised Bush, as he did at their second meeting at the White House in April, when he abandoned Operation Distance.

Brown had hoped to use this year to map out a new global agenda for the "post Bush era," including a shake-up of institutions like the United Nations. But this may be overtaken by events, because there are a lot of pressing issues to discuss with the outgoing President on top of Iraq and Afghanistan - the global credit crunch, oil and food prices, a world trade deal, Iran, Burma and Zimbabwe to name just some.

In any case, Bush has not gone yet. He may be seen as a lame duck but he's still walking. He looked to me rather in denial that his time is almost up. He doesn't regard his trip as a "farewell tour" and couldn't even admit this was his last visit to London as President, when surely it is. As he told Sky News: "Six months is a long time in a presidency." Ominous.