When the US President George W. Bush was asked recently about the "special relationship" between the UK and US, he gushed about Tony Blair and Winston Churchill but made no mention of Gordon Brown.
His slight faux pas illustrated a broader point: transatlantic relations have cooled since Blair left office as Brown has edged away from the Bush administration, partly as a way to differentiate himself from his predecessor.
A show of unity is expected this week when the prime minister visits the US for the second time since taking office. But arguably the most important meetings will be the "get-to-know-you" sessions with the three main US presidential candidates: John McCain, Hillary Clinton and Barack Obama.
"Gordon Brown is holding his breath until the next president is sworn in," says Julianne Smith, at the Centre for Strategic and International Studies. "That is the moment when he hopes to revitalise and reinvent the US-UK relationship."
Even so, Brown has far from written off Bush. Iraq, Afghanistan, Iran and the credit crisis are pressing issues that will not wait for a presidential election. "We're taking a pragmatic approach," said one Downing Street official. "We have to get going on these issues right now. There is no complacency."
Those who have seen the two leaders interact say the personal chemistry is warmer than public body-language suggests. Calls between London and Washington are less frequent and the bonhomie has gone, they say, but the personal foundation for the alliance is sound.
The wars are likely to top the agenda. On Afghanistan, the US has asked British forces to take command of the Nato operation in southern Afghanistan for two years. Brown has yet to respond to the request, which would amount to a significant commitment.
Prickliest conversation
But the prickliest conversation is likely to involve Iraq. British officials are keenly aware that the recent fighting in Basra has cast an unwelcome spotlight on their pull-back from the city. Longstanding US complaints about Britain's "Kipling-esque" approach - a propensity for playing off one faction against another - have been revived.
Bush and other senior US officials have remained publicly supportive of the UK withdrawal, which was first proposed by Blair. But diplomats acknowledge that "fundamental disagreement"exists in private over strategy in Iraq, particularly in Basra.
Both sides have begun a rethink of strategy. Calling a pause to the British drawdown has allowed the government to sidestep calls in parts of the Bush administration for the US to send reinforcements to Basra - which would be highly embarrassing for Brown. Even so, some creative thinking is under way about how to support UK efforts, according to diplomats. The White House meeting will be an opportunity to take stock of recent events.
While such "operational" matters are likely to dominate an agenda with a president entering his final year in office, Brown is not shying away from longer-term topics, to the surprise of some officials on both sides of the Atlantic.
The highlight of the trip is likely to be meetings with the presidential candidates. Old diplomatic hands say it is a "golden opportunity" to prepare the ground for what could be a significant realignment in transatlantic relations.
The sensitivity of mid-campaign diplomacy is not lost on Brown. All publicity will be closely choreographed so there is not "a cigarette paper" of difference in his approach to all three presidential hopefuls, according to one diplomat. "It would be madness to put all his eggs in one basket," said an insider.
