The substance of the disagreement - when and how to put a peacekeeping force into Kosovo - is moving towards a conclusion as Nato finalises its plans. But the argument has left a nasty taste in Washington, where Britain is seen as having lacked any sense of the political problems that the debate on ground troops poses for other alliance nations. "We need to be better co-ordinated and not air everyone's differences and opinions in public," a White House official said yesterday.
The Foreign Secretary's visit to Washington came as the US press reported that President Bill Clinton had intervened to press Britain to damp down its rhetoric. The President spoke with Tony Blair for an hour-and- a-half on Tuesday night, the New York Times reported. He expressed his "displeasure" with the rift, and asked Mr Blair to "please get control" of the people who appeared to be speaking on his behalf, the report said.
Britain has not suggested mounting a land invasion of Kosovo, but it has wanted a public debate about the need for a peacekeeping force, and the possibility that it might enter Kosovo before a deal with Belgrade.
Neither the US nor most of the European allies would countenance using ground forces to confront Serb troops. Though all support, and most will participate, in the peacekeeping force. The President sought to take some of the sting out of the row on Tuesday by changing his language, if not policy. "I and everyone else has always said that we intend to see our objectives achieved and that we have not and will not take any option off the table," he said when asked about putting infantry into Kosovo.
The Foreign Secretary was to meet with Secretary of State Madeleine Albright and leading members of Congress yesterday. In a display of transatlantic unity, he was also set to appear on several television shows with Ms Albright and have dinner with her. Every effort will be made to show that there is no disagreement over strategy in the Balkans, despite repeated statements from London and Washington that clearly differed over the conditions for the deployment of infantry into Kosovo.
Discussions in Brussels centre on a 45-50,000 strong force that would go into Kosovo after a peace deal. It would have a US component of about 7-8,000, according to the Pentagon. US national security officials may meet with the President today to confirm the make-up of such a force, if discussions with Moscow and Belgrade advance, according to White House officials.
Americans may have a higher tolerance of US casualties in Kosovo than either the White House or the Pentagon believes, according to poll findings released on Wednesday by a foreign policy thinktank in Washington. But President Clinton's reluctance to take the lead in the the allied military operation, as seen in his constant deferral to Nato, is fully in line with American opinion which does not want the US to play the role of world policeman.
According to the poll, conducted by the Programme on International Policy Attitudes last weekend, 65 per cent of those asked said they would accept 25 US casualties in a ground war in Kosovo, but a full 60 per cent said that they would accept ten times that many - so long as the operation succeeded in driving Serbian forces out of Kosovo.
Mr Clinton and his Defence Secretary, William Cohen, are believed to have resisted the deployment of ground troops in combat for fear of public reaction to casualties, the so-called "body-bag syndrome".
Challenging the notion that Americans might accept casualties in theory, but not in practice, the pollsters pointed out that the impact on US opinion of the 18 US deaths in Somalia in 1993 was not as negative as is commonly believed. Fewer than half - 40 per cent of those polled at the time - thought that the US should abandon its intervention as a result.