Worldview/Paul Gillespie: According to the British Foreign Secretary, Jack Straw, the European Union "would reap a whirlwind if we push Americans into a unilateralist position in which they are at the centre of this unipolar world".
And Peter Mandelson, the former Northern Ireland Secretary, told students in Kent University that if Europeans allow the international system develop so the US is in one corner and Europe in the other, they will squander the chance of gaining influence. Instead the US would go it alone, creating coalitions of the willing "like a sheriff and his posse".
It may be assumed these views reflect those of Tony Blair. Many are puzzled by his dogged determination to support US policy on Iraq, even to the extent of defying a United Nations veto or majority against military action.
This political/strategic explanation avoids the kind of pop psychology too often used to explain Blair's policy. He has always argued that Britain has a special role to play as a bridge between the US and Europe after the end of the Cold War, following Britain's strategic decision to become a junior partner to the US after the second World War. His standing in Europe has helped bear out the case he has made.
The next few weeks will put his policy to the test as never before and give him an extraordinary power if he chooses to use it. George Bush badly needs his support to give himself international cover for the US domestic audience - and to maintain what has become an effective bipartisan policy on Iraq, in which the Democrats have been quite mute in criticising the Bush approach. Britain underpins this coalition of the willing. Blair also faces huge political risks if he proceeds to war without a UN mandate. This week's remarkable diplomatic developments saw France gain Russian support for refusing a mandate. That exposes Blair to deep political damage at home and to a potential evaporation of influence in Europe.
Of course, the jockeying for support in coming days is also a game of poker being played for very high stakes. Henry Kissinger said the spectre of allies lobbying against one another "has not happened in 50 years of previous controversies", calling it a "sort of 19th-century balance of power game".
Another geopolitical realist, Zbigniew Brzezinski, put it like this: "At stake is not Iraq. At stake is our global role." He went on: "Doing it all by ourselves on our terms, ignoring the rest of the world, shouting loudly that if you're not with us you're against us, is not going to be a very successful policy."
The question Blair, Straw and Mandelson must answer is whether Brzezinski's characterisation of the new US policy and its global role has not already come to pass. Blair's intervention last August was clearly influential in convincing Bush to go the Security Council direction on Iraq, resulting in the unanimous passing of Resolution 1441. Blair believed that swayed the balance of power in the US back towards the multilaterals led by Colin Powell.
But it can be convincingly argued that this was more a tactical than a strategic shift. Other policy developments since last autumn have gone decisively in the direction of a more assertive and unilateral US policy. Such thinking suffuses the National Security Strategy adopted in September, which speaks repeatedly of US primacy and the need to protect it against any combination of competitors.
International organisations and alliances, while still necessary, will have to be adapted to these new realities. The confident tones with which these views are expressed represent a convergence between the neo-conservatives, assertive nationalists and conservative realists who were competing to define the Bush administration's international priorities.
So the unilateral horse may already have bolted. That seems to be the conclusion drawn not only in France, but also by the Russians this week. It calls for quite a new set of tactics, they believe - hence their insistence that they will not allow a resolution mandating war to pass at the Security Council.
If the horse has bolted Blair faces a huge choice between opting into another junior partnership, this time as a deputy sheriff in the posse, or going with the main European states into an alternative partnership to balance it.
It would be rational - and sensational - (but alas, unlikely) if he were to refuse to go along with a US-led war without another mandate. That would really exercise his influence as a bridging player across the Atlantic.
Giving the inspectors more time would force the US to make a more convincing case, encourage more debate about the US role at home and abroad and restore Blair's political standing in Britain and Europe. But it would also upset Bush's domestic political timetable possibly by postponing the war to the autumn. Preventing this is a key factor in the administration's calculations, in addition to the difficulty of fighting in hot weather or the humiliation of bringing US troops home without a regime change in Iraq.
That conflation of US war objectives, between disarmament and regime change, contains the kernel of the transition referred to by Straw and Mandelson. Regime change grows out of the new security doctrine, Iraqi disarmament out of the older, now redundant one.