The images of protestors burning British flags across the world last week signalled the start of a new diplomatic era of isolation and hostility unknown since the days when Maggie bestrode the planet wielding her handbag.
The tragedy for Prime Minister Tony Blair is that by following his convictions he has destroyed each of the foreign policy pillars that defined his worldview. He had a foreign policy that was based on the international rule of law, European engagement, and engaging the Americans in a progressive project for international community. Today he must face the facts: by exercising his incredible willpower to do the right thing, he has ended up in exactly the wrong place.

People I speak to from Sweden to South Africa warn that Blair is now widely seen as an American poodle who puts power politics above international law. A Saudi journalist describes the exasperation: “The British are trying to be more royalist than the king. It’s worse than Guam, and that’s a US territory.” A South African who knows Mbeki well, warns: “I’ve detected a major realignment, among those in power in South Africa, away from Tony and towards Jacques. We feel that Chirac is ‘someone we can do business with’. Let’s go for the cynical bastard who wants to rape us rather than the missionary who wants to save us”. Even in sympathetic European countries the outlook is bleak: a confidant of the Swedish Prime Minister fears that they will have trouble working with Britain “now that you have put your relationship with the Americans above international law”.

In short, the political capital and respect that was so hard won – and so vital to the success of Blair’s global strategy – in the years after 1997 has all but dissipated. So how can the diplomatic damage be repaired?

First, the European dilemma: how do we avoid being seen as “roast beef-eating war monkeys” on the margins of importance? While we were trying to re-order the world, Jacques Chirac was busy vying for leadership of Europe. Chirac may have upset “New Europe” with his offensive language, but we must not delude ourselves into thinking that it is the French who are isolated. No other centre-left party in the European Union shares the position of the Blair Government. Even the right-wing governments of Berlusconi and Aznar that supported US diplomacy have not committed any troops. The French and Belgians are already planning an inner core to co-operate on defence and other areas – leaving us on the outer fringes. The danger is of Blair becoming a leader with both hands tied behind his back – unable to act in the economic realm because of his “euro problem”, excluded from the political realm by his “American problem”.

Second, the transatlantic relationship. Far from being a bridge between America and the rest of the world Britain is seen by many as a shadowy continuation of a “rogue superpower” – subject to all the resentment which the toxic cocktail of Rumsfeld, Cheney and Richard Perle have stirred up. Blair’s principled attempts to multilateralise America are too subtle to be picked up by foreign publics and medias – who see him as simply falling into the template of knee-jerk support for the United States established by Thatcher’s support for the Libyan bombings. This perception is not simply damaging to British interests – it is also unhelpful to America. As one seasoned British diplomat remarked to me: “The Americans have been trying to trade on our credibility in the world. But we don’t have any to give – we need it all for ourselves”.

Finally, the transition from selfish Little England to ethical internationalist has been set back. In Blair’s first term he sought to undo the worst memories of unprincipled foreign policy with an appeal to a vision of an international community. “Beef wars” with Europe gave way to negotiated settlements; memories of Thatcherite support for Apartheid were banished by inviting Mandela to address the UK parliament; the ghost of inaction over Bosnia and Rwanda was laid to rest with swift humanitarian interventions in Kosovo and Sierra Leone. Britain placed itself at the forefront of moves to promote an International Criminal Court, rules for intervention in internal conflicts and multilateral regimes on everything from arms control to climate change. And yet, today, we are more likely to be seen as the country that ignored the UN charter and embarked on a new type of war, a pre-emptive strike in defiance of international law and global public opinion.

Even many of those who disagree with a war on Iraq cannot suppress their grudging admiration for Blair’s vision, idealism and energy. He is the Labour leader who has come the closest to articulating a vision of the international community which draws on and encapsulates the values of the centre-left. Blair is also a rare creature of his time. Instead of relying on narrow calls for national interest, he has always managed to frame his principles in a universal language which could touch people across the world.

Yet Blair now faces his biggest challenge so far: rebuilding an international policy that it is in tatters – not because he has consciously abandoned it, but because it has become a casualty of events. Blair realises that the first step is to reassert his attachment to principle and his independence from the United States by driving through a just peace in Iraq, as in Palestine, even if that may mean bloodying American noses along the way.

· Mark Leonard is Director of The Foreign Policy Centre (www.fpc.org.uk), and writes a regular online column for Observer Worldview