Mr Blair must not betray the Democrats by his support for President Bush

It is in Mr Blair's interests to take account of at least the possibility, however doubtful, of a Democrat in the White House

Whatever it might have been in other circumstances, the state visit of President Bush to London on 19 November looms as an event fraught with hazard. Not, it should be said, for the President himself, who can hardly do other than gain in a pre-election year from being welcomed by the Queen at Buckingham Palace and Tony Blair at No 10. The problems of the visit, perhaps in the run-up to a Hutton report, are rather for Mr Blair. It will throw yet another spotlight on the closeness of the Bush-Blair relationship which Mr Blair could probably do without in the midst of a difficult autumn at home and in Europe.

It may also help to define what, if any, Blair factor there will be in the coming US election. For whatever his troubles at home, Mr Blair remains a figure of some potency in US public opinion. So much so that some Anglophile US Democrats are beginning to wonder how his relationship with Mr Bush will play in election year. "Tony doesn't understand how fast America changes," one said recently in private. "The Presidential election could be close, and Blair'd better not get in the way of the Democrats."

However brutal this assessment, it has a point. For there is a marked convergence between what Mr Blair needs to do in his own domestic and European interests, post Saddam, and what would help the Democrats, as Mr Blair actually has every interest in doing if he wants to repair the fractured US-European relationship. And that means exploiting his steadfast support for Mr Bush by being a good deal tougher in seeking benefits in return.

The issues, of course, are many and various. The sharpest, most immediate - and also most domestic - happens to be the negotiation Lord Goldsmith, the Attorney General, is engaged in about the British detainees in Guantanamo Bay. If the US refuses, as it has so far appeared to, not only to allow them to be tried in US federal civil courts but to allow them the right to appeal decisions of a military tribunal to a judicial body apart from the Pentagon, does Britain accept it? Or does it reluctantly draw a line under the discussions and propose bringing back the detainees, thus provoking a rupture between London and Washington?

This issue, unmentioned in Jack Straw's speech to the Labour conference yesterday, is important in itself. But if Guantanamo isn't resolved in the negotiations which were Mr Bush's only concession to Mr Blair on the subject when he visited Washington in July, it will become a symbol of the limits London is prepared to apply, in this case in the interests of British justice, to its loyalty to the US.

And that is relevant to larger and more long-lasting issues. In his speech on Tuesday, Mr Blair repeated his eloquent - and actually incontrovertible - defence of the principle of engagement with the US on issues ranging from Africa, to the Middle East, world trade and the Kyoto agreement. Some Blairite politicians have been urging the Prime Minister to make this last difference a more visible one up to and including a real row. But the argument applies in other areas cited by Mr Blair on Tuesday. Around the time of Mr Bush's inauguration officials close to Mr Blair regularly cited, as one of the potential benefits of the new administration over the old, its commitment to free trade. Yet you don't have to ignore the continuing scandal of the slow pace of reform of European agriculture policy to accept that elements of protectionism - notably on agriculture - in US legislation belied that aspiration.

Above all this may be relevant in the Middle East. You can argue that one of the undoubted quid pro quos Mr Blair achieved for his support on Iraq was the commitment of Washington to the road map envisaging a two-state solution for Israel-Palestine. That achievement shouldn't be belittled; but it's open to question whether it is going to be translated into real progress ahead of a Presidential election.

In an interesting exchange at a European summit way before 11 September, 2001, Mr Blair criticised the EU for its condemnations of Israeli policy, arguing that only by being even-handed could it expect to be listened to by Tel Aviv. Chris Patten, the EU foreign affairs commissioner, replied by saying, in effect, that Israel had the US and that maybe the balance would really be struck by more overt EU support for the moderate Palestinian case.

To be fair, the UK has been rather more forceful than the US in condemning Israel's counter-productive assassinations of Palestinian militants. What is much more doubtful is whether it is also prepared to urge the US - if necessary publicly - to keep up the pressure on Israel to create the conditions for serious negotiations in the run-up to the American elections.

You don't have to buy into the more exotic anti-war rhetoric of Labour's old "peace campaigners" in yesterday's deeply anti-climactic debate on Iraq at Bournemouth to realise that Mr Blair still has a job to convince the public as well as his party that he is capable of an independent foreign policy. Some of the talk yesterday about an instant withdrawal of US and British troops is so much fantasy. But as Peter Riddell argues towards the end of his illuminating new book on the US-UK relationship, Hug Them Close, it is possible as well as desirable to become more independent without being hostile.

This matters in Europe, where Britain needs to work harder for common European positions, not least with France, and not least on defence. Gordon Brown's argument on Monday that Britain can be a "beacon" rather than a "bridge" between the US and Europe is thought-provoking. But it is also, more self-servingly, a vehicle by which he can persuade the Eurosceptic press that he shares some of their concerns, while persuading the party that he is capable of standing up to the US. The real danger is that by refusing to stand up more vigorously for existing British policy in its dealings with the US, Mr Blair risks, in Mr Riddell's words "being ignored in much of Europe and being taken for granted in Washington."

But the new context to all this is the admittedly tentative resurgence of Democrat forces in the US - a resurgence which Mr Blair should wholeheartedly welcome if he is true to his instincts on foreign policy, if only because it is more likely to realise his internationalist goals than a right wing Republican one is. Nobody is suggesting he doesn't need a relationship with Washington, much less that he should land himself in the kind of trouble John Major did by being perceived to lend a covert helping hand to George Bush senior. But the relationship now urgently needs to be more candid than it has been. And it is in Mr Blair's interests to take account of at least the possibility, however doubtful, of a Democrat in the White House. And at the very least not to subordinate British interests - and to some extent his own instincts - to an uncritical support for Mr Bush which would actually hinder the progress of the Democrats. It would be a tragic irony if the tide suddenly turned in the US and Mr Blair found himself beached with only a defeated Republican President for company.

d.macintyre@independent.co.uk