In an interview General Wesley Clark, Nato's Supreme Allied Commander in Europe, criticised those who have suggested Europe may be able to develop its autonomous military capability away from Nato structures.
Reflecting on the outcome of the Kosovo campaign, General Clark also conceded that President Slobodan Milosevic was "strong and secure at this moment" despite his status as an indicted war criminal.
The general attended yesterday's meeting of Nato foreign ministers which debated Europe's plans to set up a rapid-reaction force of 40-60,000 troops by 2003, an initiative, launched at the weekend, which has provoked tension with the US.
Talking during a break in the discussion, General Clark said: "There has always been a recognition that Nato operates on the basis of shared risks, shared burdens and shared benefits. What's been clear for all these years is that on both sides of the Atlantic we have been in the same lifeboat.
"Some of the rhetoric of the last six months has led people to believe someone was about to launch a smaller lifeboat out of the larger lifeboat".
General Clark, whose bombing campaign helped to bring about the withdrawal of Serb forces from Kosovo, said there was a danger Europe's ambitions would be misinterpreted in the US.
Although he mentioned no European country, General Clark's comments are almost certainly directed at France, which stays outside some of Nato's structures and advocates an independent European defence capability. Such talk, he said, could fuel isolationist argument in Washington.
"Those who promote rhetoric on one side of the Atlantic have to recognise that those on the other side will read it, although they may not fully understand it or use it for their own purposes," he said. "For that reason there is a certain degree of risk".
Asked if that was a manageable risk, he answered: "I am not going to make that kind of judgement". General Clark argued, however, that the language arising out of the communique from the Helsinki EU summit at the weekend was reassuring. It said the EU would "develop an autonomous capacity to take decisions and, where Nato as a whole is not engaged, to launch and conduct EU-led military operations in response to military crises".
Many details, including whether Nato will have the right of "first refusal" in a conflict and mechanisms for avoiding duplication have yet to be resolved. But General Clark argued that development of a European defence identity was "inevitable" and "timely", and pointed to Europe's new commitment to increase resources going into defence.
All sides of the debate agree that the Kosovo campaign illustrated how far Europe lagged behind the US in military capabilities, particularly in intelligence and heavy lift. General Clark refused to comment on whether European ambitions will be achieved on target.
His conduct of the Kosovo bombing campaign was criticised in Washington and his early retirement, due in May, was seen by many as a snub. Yesterday the general said he had always intended to step down next year and claimed he was given political support. That, he said, included the time of his stand-off with the British commander on the ground, General Sir Michael Jackson, over orders to prevent the Russians taking the military airbase in Pristina. But he said he had learnt lessons from Kosovo, in particular that, once a threshold had been reached in a conflict, force should be escalated rapidly. Accepting that Mr Milosevic was unlikely to be ousted soon, General Clark said his continuing presence was a fundamental barrier to democratisation of the region.
Yesterday's meeting of defence ministers was characterised by the concerns of Nato countries which are not members of the EU, about their role in the new military structure. Turkey, despite being given status as a candidate for EU membership last weekend, outlined its anxiety about its role in the new defence environment. The Foreign Secretary, Robin Cook, said: "Turkey has expressed its own view - that it wishes to make sure that its interests as a member of Nato are represented".
Some European ministers voiced concern over the prospect that Washington will proceed with its national missile defence system, which some states believe may destabilise the global security environment.
Ministers also debated the continuing problems of the Balkans, where Mr Cook said Nato was playing a central role in the attempt to "break the cycle of violence".