The presidential contest is over but the race for the White House has only just begun. The new, nail-baiting, make or break battle is over which European leader will be the first to receive an invitation from President Obama.
A joke along these lines is doing the rounds in Whitehall and no doubt in other similarly sized countries, too. The joke is deadly serious. What Gordon Brown would give to utter the words "I've been invited to Washington by President Obama..." before any other leader does so.
The joke is also significant because the competitive hunger for the invitation is a reflection of the global influence that Obama could exert in his opening months. As one British cabinet minister puts it, "Which leader will want to say 'no' to Obama if he makes a request for support?" There is such international goodwill and a desire from most leaders for a close association that Obama will be in a position to form potent alliances and make waves in foreign policy almost immediately.
Such is the sweeping euphoria in the US that he is doomed to disappoint on other fronts. How could he do otherwise when expectations are so great? On a more epic, global scale there are echoes in the reaction of recent days with the soaring optimism after Tony Blair's victory here in 1997. The heady excitement in Britain and beyond more than a decade ago was bound to end in disappointment. Few of those dancing in the streets had bothered to read the cautious, incremental manifesto on which the supposedly historic election victory had been based.
In 1997, the scale of Labour's win was mindblowing; the programme on which it was based was not. In the case of Obama, it is the enormity of the challenges that is so daunting, as he noted in his extraordinarily measured and calm victory speech on Tuesday night. Of these, the economic crisis will be an almost certain source of disillusionment. Voters in the US are unlikely to remain euphoric as a recession bites.
But in the field of foreign affairs, Obama has a chance to make waves almost immediately. This is partly because of the near-global goodwill, as potent as the coalition of support for the US that formed spontaneously after 11 September 2001 and less ambiguous in its enthusiasm. His chance arises also because of the brutal dynamics of power. George W Bush was a lame duck. At the start of a new era, with the possibility of eight years in power, Obama can act.
From the perspective of the British government, there is a mixture of tangible excitement and caution at such a prospect. The caution is as important as the excitement in an era when British foreign policy is less destructively crusading than it was a few years ago.
Senior government insiders point out that, over the past few years, the Bush administration was already acting on a more multilateral basis in relation to North Korea and Iran. Therefore, there will not be a revolutionary leap from a rigid, swaggering unilateralism to a new joyous phase of multilateralism. British ministers also fear that the economic crisis could be so great in the US that the new President becomes almost immediately diverted from foreign affairs.
Nonetheless, the sense of excitement within the Government is at least as strong as the wary finger-crossing. Generally, ministers speak positively of a shift from the "learnt multilateralism of the Bush era to Obama's instinctive multilateralism". More specifically, there is hope that Obama will attempt to reignite the Middle East peace process.
On Afghanistan, ministers note a similar set of priorities to Britain, linking military action with social and economic packages. There is even some small optimism that Obama might be able to persuade other countries to share the military burden. Government insiders also note enthusiastically the commitment to addressing climate change.
Finally, there is almost relief that – for a time at least – Europe and the US will be working closely together after the divisions over Iraq, working so closely that the French President, Nicolas Sarkozy, and the German Chancellor, Angela Merkel, would also give as much as Brown to be the first European visitor to the White House.
Inevitably, there will be momentous challenges too. What will Obama decide to do about Iran? What if an initiative on the Middle East ends in failure? Iraq is still unstable and Afghanistan is an ill-defined conflict of uncertain outcome. Following the traumas of recent years, some of them self-inflicted, the British government is under no illusions that foreign policy is about to become suddenly straightforward.
But whatever happens next, the election of Obama leaves the current government less exposed. It moves from being the isolated, crusading ally of the Bush administration to join a crowded group of countries paying homage to the new US regime. At the very least, the Atlanticist calculations for this timid New Labour administration become less contorted.
Tony Blair supported Bush above all because he feared he and his party would be seen as anti-American and soft on defence if he did not do so. His moral crusade followed his fundamental strategic decision that he would not break with the US. If this sounds too crude an assessment, imagine if France and Germany had called for an invasion of Iraq and President Bush had been opposed to such a move. Blair's moral crusade would have put the case against war in alliance with the US. I suspect he would have done so with even more passion if working in alliance with a popular President Obama.
Gordon Brown, too, has agonised over relations with George Bush. How to appear slightly distant compared with his predecessor, but not so much that the ardent Atlanticist newspapers in Britain would be able to detect even a hint of anti-Americanism? Brown never came up with a convincing answer.
Now he does not have to ask the question. Yesterday, I argued that, for different reasons, neither Brown, nor David Cameron were in a position to claim credibly that they were the British equivalent to Obama, although both have tried to seize the mantle almost as if voters in Illinois really had them in mind as they headed for the polling stations. Brown is a long-serving incumbent; Obama launched his crusade as an opponent to a long-serving administration. Cameron is a Tory with views and a background far removed from those of Obama's. Some cabinet ministers dare to wonder whether Obama's triumph marks the end of conservatism in a way that will propel them to victory too. Opinion polls here suggest that they are being highly optimistic.
Obama's impact here will be less on the electoral fortunes of Brown, but in the way he develops his foreign policy. Ironically, a combination of the economic crisis and Obama's election means that Brown is enacting Blair's theoretical foreign policy that was blown apart by Iraq. Suddenly, Brown is engaged in Europe while seeking to be the strongest ally of the US. Will that be enough to make him Obama's first guest at the White House? Brown will not be laughing if someone else gets there first.