The United States backed away from a showdown with Britain yesterday over defence, saying it was confident that any deal negotiated by Tony Blair with his European Union partners would not undermine the transatlantic Nato alliance.
Donald Rumsfeld, the hawkish and outspoken US Defence Secretary, went out of his way not to attack a deal struck by Britain, France and Germany that would, for the first time, give the European Union an operational military planning capability independent of Nato.
Washington's reservations about the scheme are the main reason that no formal announcement has been made, despite the fact that the detail of the plan was leaked to the French press last week.
Mr Rumsfeld, who is visiting Brussels for a two-day meeting of Nato defence ministers, did not endorse the package of measures. However, he said that he was "confident that things will sort through in a way that we have an arrangement that is not duplicative or competitive of Nato".
In an uncharacteristic display of diplomacy, he ducked questions as to whether the EU needed to have its own operational military planning capability. The Nato secretary general, Lord Robertson of Port Ellen, also took care to avoid any direct attack on the EU's defence plans.
During his visit to Brussels, Mr Rumsfeld had sent out contradictory signals. When he arrived on Sunday he took a harder line, telling Washington-based reporters that countries would "have to have a very good reason" for wanting to do "anything that puts at risk" the Nato alliance. Countries benefiting from Nato's existence do not want "something that would inject an instability into it", he added.
His display yesterday will hearten supporters of the EU defence plan, indicating that the US has been convinced to hold off from any direct criticism of the unpublished plan. Detailed discussions are still taking place as London holds talks with "partners and allies" pending finalisation of the paper.
With domestic eurosceptics waiting in the wings to attack the plan, Mr Blair needs to ensure that neither Washington nor Nato attack it openly.
When the EU launched its rapid reaction force, Mr Blair was able to withstand an onslaught in the British eurosceptic media, and still emerge with support for the policy in the opinion polls. At that time, the US administration and Lord Robertson argued that the initiative would not undermine Nato.
The most sensitive element of the proposal is that the EU would, for the first time, have an autonomous operational planning capability, a long-term ambition of France and Germany. This would be created by beefing up a strategic planning cell that already exists in Brussels but would be an ad hoc arrangement for specific missions, rather than a standing facility.
Berlin and Paris agreed, in exchange, to give up their scheme to have a new military headquarters for the EU in the Brussels suburb of Tervuren. This is seen as vital by Britain, which worries that it would surrender influence over another EU initiative to the French and Germans, and would be unable to steer its development. While Britain insists the new blueprint would not undermine Nato, there are tensions inside Whitehall. The Secretary of State for Defence, Geoff Hoon, fuelled speculation yesterday that he is hostile to the plan by failing to give a press conference. Mr Hoon will meet Mr Rumsfeld today.
Meanwhile, Nato sources said they had received assurances from the UK that key issues have not been settled. Lord Robertson, echoed Mr Rumsfeld's caution. "I can't imagine anything being agreed by Prime Minister Blair in London that would undermine the integrity, strength and pre-eminence of Nato as the security organisation of first choice," he said. The issue of a military headquarters is being discussed as part of a wider package of measures on defence. The EU's draft constitution, which is due to be agreed at a summit of EU leaders next month, will outline plans for a groups of nations to co-operate on military issues.
It may also include a mutual defence clause, something that the UK is trying to weaken for fear that it will undermine the role of Nato.